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  • Inorganic Chemistry  (5,391)
  • Life and Medical Sciences  (2,512)
  • Aerodynamics
  • Aircraft Design, Testing and Performance
  • Industrial Chemistry
  • Seismology
  • 2020-2024  (24)
  • 1975-1979  (6,230)
  • 1950-1954  (3,777)
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Keywords
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Years
Year
  • 1
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    Hamburg in der Novemberrevolution von 1918/19 (2024)
    transcript Verlag | transcript Verlag
    Details
    Publication Date: 2024-05-13
    Description: Die Novemberrevolution von 1918/19 erschütterte die Tiefenschichten der politischen und gesellschaftlichen Ordnung der Metropole Hamburg. Diese vielschichtige Transformation wird anhand ausgewählter Akteur*innen, Institutionen und Ereignisse mit Beiträgen aus der neueren Revolutions-, Konflikt- und Kriegsforschung sowie aus der Kulturwissenschaft, der Geschichts- und Sozialwissenschaft nachgezeichnet. Die Beiträger*innen des Bandes durchleuchten die Dynamiken des revolutionären Wandels im umfassenden Dispositiv der urbanen Machtverhältnisse in ihren diskursiven Formationen: im Geschlechterverhältnis, in den Klassenverhältnissen, in der Wirtschaft, im Bildungswesen, im Film, in den Utopien und Vorstellungen der Menschen der Zeit. Die Beschreibung der dynamischen Umbrüche schließt die Nachbarstadt Altona und die Region ein und verbindet somit Lokales mit Nationalem und Globalem.
    Keywords: Revolution 1918/19 ; Hamburg ; Politik ; Gesellschaft ; Norddeutschland ; Wahlen 1919 ; Film ; Weimarer Republik ; Globalgeschichte ; Deutsche Geschichte ; Bismarck ; Metropole ; Seismologie ; Kulturgeschichte ; Geschlecht ; Stadt ; Sozialgeschichte ; Europäische Geschichte ; Geschichte des 20. Jahrhunderts ; Geschichtswissenschaft ; Politics ; Society ; North Germany ; Elections 1919 ; Weimar Republic ; Global History ; German History ; Seismology ; Cultural History ; Gender ; City ; Social History ; European History ; History of the 20th Century ; History ; thema EDItEUR::N History and Archaeology::NH History::NHD European history ; thema EDItEUR::N History and Archaeology::NH History::NHT History: specific events and topics::NHTB Social and cultural history
    Language: German
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  • 2
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    Homogenization of magnitudes of the ISC Bulletin (2024)
    Oxford Academic
    Details
    Publication Date: 2024-04-05
    Description: This article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2023. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy. All rights reserved.
    Description: We implemented an automatic procedure to download the hypocentral data of the online Bulletin of the International Seismological Centre (ISC) in order to produce in near real-time a homogeneous catalogue of the Global and EuroMediterranean instrumental seismicity to be used for forecasting experiments and other statistical analyses. For the interval covered by the reviewed ISC Bulletin, we adopt the ISC locations and convert the surface wave magnitude (Ms) and short-period body-wave magnitude (mb) as computed by the ISC to moment magnitude (Mw), using empirical relations. We merge the so obtained proxies with real Mw provided by global and EuroMediterranean moment tensor catalogues. For the most recent time interval (about 2 yr) for which the reviewed ISC Bulletin is not available, we do the same but using the preferred (prime) location provided by the ISC Bulletin and converting to Mw the Ms and mb provided by some authoritative agencies. For computing magnitude conversion equations, we use curvilinear relations defined in a previous work and the chi-square regression method that accounts for the uncertainties of both x and y variables.
    Description: H2020 EU project RISE contract n. 821115
    Description: Published
    Description: 1771-1785
    Description: OST2 Deformazione e Hazard sismico e da maremoto
    Description: JCR Journal
    Keywords: Statistical methods ; Statistical seismology ; Earthquake source observations ; Seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 3
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    Active Flow Control: Recent Advances in Fundamentals and Applications (2023)
    MDPI - Multidisciplinary Digital Publishing Institute
    Details
    Publication Date: 2023-11-30
    Description: Active flow control (AFC) utilizes local active perturbations to induce changes in global flow behavior that result in aero/hydrodynamic performance improvement. It has been a vibrant research area with potential applications in a wide range of engineering fields. This Special Issue is a collection of 11 excellent research papers published in Actuators, showcasing and discussing new advances in both fundamental and applied AFC technologies.
    Keywords: Active flow control ; Actuators ; Aerodynamics ; Synthetic jets&nbsp ; bic Book Industry Communication::T Technology, engineering, agriculture::TB Technology: general issues
    Language: English
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  • 4
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    Role of crustal fluids and thermo-mechanical structure for lower crustal seismicity: The Gargano Promontory (southern Italy) (2023)
    Elsevier
    Details
    Publication Date: 2023-02-20
    Description: Several regions around the globe are characterized by a seismically active lower crust, at depths where litho­logical and thermal conditions suggest stress release by ductile flow. The Gargano Promontory (GP, southern Italy) is an example where a recently installed seismic network has recorded an intense seismic activity at depths between 20 and 30 km, i.e. in the lower crust. The GP is located in proximity of the Gargano-Dubrovnik line­ament, a seismogenic zone separating the central and southern Adriatic basins. These two basins constitute sites of sediments accumulation since Tertiary times. Another important basin in the region is represented by the Apennine foredeep, that includes the Candelaro area. We analyze the possible mechanisms controlling the dis­tribution of seismicity in the GP to identify the factors that make the lower crust seismically active. To this aim, we construct a thermo-rheological model of a layered continental crust, calibrated on the basis of geometrical, lithological and thermal constraints. The model takes into account various crustal lithologies, the presence of fluids in the crystalline basement, lateral variations of geotherm and stress field. The numerical simulations show that the presence of fluids is a key factor controlling the cluster of seismicity in the lower crust. Moreover, the presence of water in the upper crystalline basement and sedimentary cover provides a plausible explanation for upper crustal seismicity in a zone of very high heat flow SW of the GP. The distribution of the seismicity is probably affected by the composition of the crystalline basement, with mafic bodies injected into the crust during the Paleocene magmatic phase that affected the Mediterranean region. In addition, fluid accumulation and overpressure may occur along detachment levels in the lower crust, leading to clustering of the earthquakes. Based on our findings, we hypothesize that the presence of hydrous diapiric upwelling(s) in the upper mantle can feed a deep fluid circulation system, inducing lower crustal seismicity.
    Description: Published
    Description: 103929
    Description: 4T. Sismicità dell'Italia
    Description: JCR Journal
    Keywords: Lower crust ; Rheology ; Seismology ; Geotherm ; Numerical modeling ; Gargano Promontory (southern Italy)
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 5
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    SISMIKO: INGV operational task force for rapid deployment of seismic network during earthquake emergencies (2023)
    Frontiers Media S.A.
    Details
    Publication Date: 2024-04-23
    Description: The National Institute of Geophysics and Volcanology (INGV, Istituto Nazionale di Geofisica e Vulcanologia), is an italian public research institute established in 1999. Since its inception, the mission of INGV included seismic surveillance and earthquake monitoring in Italy. INGV is part of the Civil Defence system (Margheriti et al., 2021). INGV has offices in different parts of Italy and operates the Italian National Seismic Network (Rete Sismica Nazionale—RSN; INGV Seismological Data Centre, 2006) and other networks at national scale (Michelini et al., 2017). INGV also operates a temporary seismic network infrastructure, a pool of instruments used to densify seismic networks for scientific experiments or in response to damaging earthquakes and to increase monitoring capabilities during seismic sequences. SISMIKO is the operational task force of INGV whose core purpose is to rapidly deploy temporary seismic stations in response to moderate—large magnitude earthquakes or in areas where a seismic sequence is causing concerns and/or scientific interest (Moretti et al., 2016). By reducing the spatial distance between the seismic stations, temporary deployments can improve the RSN detection capability and the accuracy of the earthquake locations. SISMIKO was established in 2015 by Lucia Margheriti and Milena Moretti, so they became responsible for INGV emergency deployments of the temporary networks. SISMIKO involves INGV technicians and researchers from all over Italy, from Milano to Catania (see acknowledgments), grouped together by common interest technical and scientific issues. SISMIKO coordinates all INGV groups working on seismic emergencies (Figure 1). The data acquired by the SISMIKO temporary networks, are made available to the scientific community, without any restrictions, via italian node of the European Integrated Data Archive portal (EIDA1; Danecek et al., 2021). Datasets are archived in near real-time in the “Standard for the Exchange of Earthquake Data (SEED)” format and have an associated Digital Object Identifier (DOI). The data are used for monitoring, surveillance and for scientific research. Since its establishment, SISMIKO has installed seven temporary seismic networks, including the one used to monitor the 2016–2018 seismic sequence in central Italy (Moretti et al., 2016). The most recent activations of SISMIKO were in May and November 2022: Chianti-Fiorentino (Piccinini et al., 2022; 2023) and North Marche coast (D’Alema et al., 2022b), respectively. The following section briefly describes the history of the INGV emergency mobile network.
    Description: Published
    Description: 1146579
    Description: OST5 Verso un nuovo Monitoraggio
    Description: JCR Journal
    Keywords: SISMIKO ; Seismic emergency ; Temporary seismic network ; Real time transmission ; Seismology ; 05.04. Instrumentation and techniques of general interest
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 6
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    Seismicity catalogue for the Eastern Alps (Swath-D) (2023)
    GFZ Data Services
    Details
    Publication Date: 2023-09-01
    Description: Abstract
    Description: We present a new, consistently processed seismicity catalogue for the Eastern and Southern Alps, based on the temporary dense Swath-D monitoring network. The final catalogue includes 6,053 earthquakes for the time period 2017-2019 and has a magnitude of completeness of −1.0ML. The smallest detected and located events have a magnitude of −1.7ML. Aimed at the low to moderate seismicity in the study region, we generated a multi-level, mostly automatic workflow which combines a priori information from local catalogues and waveform-based event detection, subsequent efficient GPU-based event search by template matching, P & S arrival time pick refinement and location in a regional 3-D velocity model. The resulting seismicity distribution generally confirms the previously identified main seismically active domains, but provides increased resolution of the fault activity at depth. In particular, the high number of small events additionally detected by the template search contributes to a more dense catalogue, providing an important basis for future geological and tectonic studies in this complex part of the Alpine orogen.
    Description: TableOfContents
    Description: Seismicity catalogue Python codes & metadata Seismicity cross-sections
    Keywords: Seismology ; Seismic Waveform Analysis ; Eastern Alps ; Earthquake ; Geophysics ; Template matching ; 4DMB ; 4D Mountain Building ; EARTH SCIENCE ; EARTH SCIENCE 〉 SOLID EARTH ; EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS ; EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS 〉 EARTHQUAKES ; EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS 〉 EARTHQUAKES 〉 EARTHQUAKE MAGNITUDE/INTENSITY ; EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS 〉 EARTHQUAKES 〉 EARTHQUAKE OCCURRENCES ; geophysics ; seismology ; surface processes ; tectonics
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  • 7
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    Forearc on-shore receiver functions, station subsurface models, and fitted slab model for Cascadia (North America) (2023)
    GFZ Data Services
    Details
    Publication Date: 2023-10-18
    Description: Abstract
    Description: This data publication contains (i) a slab model of the Cascadia subduction zone, derived from receiver functions, parameterized as depth to the three interfaces: t (top), c (central) and m (Moho), in NetCDF format; (ii) the station measurements of all parameters in the model in tabular and Raysum model file format; (iii) the raw receiver functions in SAC format; and (iv) auxiliary scripts for loading and plotting the data. A total of 45,601 individual receiver functions recorded at 298 seismic stations distributed across the Cascadia forearc contributed to the slab model. For each station, 100 s recordings symmetric about the P -wave arrival (i.e. 50 s noise and 50 s signal) of earthquakes with magnitudes between 5.5 and 8, in the distance range between 30 and 100 degree, were downloaded from the Incorporated Research Institutions for Seismology (IRIS) data center, the Northern California Earthquake Data Center (NCEDC), and the Natural Resources Canada Data Center (NRCAN). After quality control, radial and transverse receiver functions were computed through frequency-domain simultaneous deconvolution, with an optimal damping factor found through generalized cross validation. The continental forearc and subducting slab were parameterized as three layers over a mantle half-space, with the subduction stratigraphy bounding interfaces labeled as t (top), c (central) and m (Moho). Synthetic receiver functions were calculated through ray-theoretical modeling of plane-wave scattering at the model interfaces. The thickness, S -wave velocity (VS) and P - to S -wave velocity ratio (VP/VS) of each layer, as well as the common strike and dip of the bottom two layers and the top of the half space (in total 11 parameters) were optimized simultaneously through a simulated annealing global parameter search scheme. The misfit was defined as the anti-correlation (1 minus the cross-correlation coefficient) between the observed and predicted receiver functions, bandpass filtered between 2 and 20 s period duration. In total, 171, 143 and 137 quality A nodes were determined to constrain the t, c and m interfaces, respectively. At the trench, 105 nodes at 3 km below the local bathymetry were inserted to constrain the t and c interfaces, and at 6.5 km deeper to constrain the m interface, representing typical sediment and igneous crustal thicknesses. A spline surface was fitted to these nodes to yield margin-wide depth models. The spline coefficients were found using singular value decomposition, with the nominal depth uncertainties supplied as weights. The solution was damped by retaining the 116, 117, and 116 largest singular values for the t, c and m interfaces, respectively, based on analysis of L-curves and the Akaike information criterion. The data set is the supplemental material to Bloch, W., Bostock, M. G., Audet, P. (2023) A Cascadia Slab Model from Receiver Functions. Geochemistry, Geophysics, Geosystems.
    Keywords: Seismology ; Cascadia ; North America ; Reveiver Functions ; Subduction ; EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS 〉 PLATE TECTONICS ; EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS 〉 PLATE TECTONICS 〉 PLATE BOUNDARIES ; lithosphere ; The Present
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  • 8
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    Hypersonic Vehicles (2022)
    IntechOpen | IntechOpen
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    Publication Date: 2024-04-11
    Description: Some sixty years after the experimental flights of the North American X-15 hypersonic rocket-powered aircraft, sustained hypervelocity travel is still the next frontier in high-speed transportation. Today, there is much excitement and interest regarding hypersonic vehicles. In fact, many aerospace agencies, large industries, and several start-ups are involved in design activities and experimental campaigns both in wind tunnels and in-flight with full-scale experimental flying test beds and prototypes to make hypersonic travel almost as easy and convenient as airliner travel. Achieving this goal will radically revolutionize the future of civil transportation. This book contains valuable contributions that focus on various design issues related to hypersonic aircraft.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science::TGMF Engineering: Mechanics of fluids::TGMF1 Aerodynamics
    Language: English
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  • 9
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    Frontiers in Chemistry: Rising Stars (2021)
    Frontiers Media SA
    Details
    Publication Date: 2024-04-04
    Description: The Frontiers in Chemistry Editorial Office team are delighted to present the inaugural “Frontiers in Chemistry: Rising Stars” article collection, showcasing the high-quality work of internationally recognized researchers in the early stages of their independent careers. All Rising Star researchers featured within this collection were individually nominated by the Journal’s Chief Editors in recognition of their potential to influence the future directions in their respective fields. The work presented here highlights the diversity of research performed across the entire breadth of the chemical sciences, and presents advances in theory, experiment and methodology with applications to compelling problems. This Editorial features the corresponding author(s) of each paper published within this important collection, ordered by section alphabetically, highlighting them as the great researchers of the future. The Frontiers in Chemistry Editorial Office team would like to thank each researcher who contributed their work to this collection. We would also like to personally thank our Chief Editors for their exemplary leadership of this article collection; their strong support and passion for this important, community-driven collection has ensured its success and global impact.
    Keywords: Green and Sustainable Chemistry ; Analytical Chemistry ; Theoretical and Computational Chemistry ; Polymer Chemistry ; Medicinal and Pharmaceutical Chemistry ; Organic Chemistry ; Nanoscience ; Catalysis and Photocatalysis ; Supramolecular Chemistry ; Electrochemistry ; Inorganic Chemistry ; Chemical Biology ; thema EDItEUR::P Mathematics and Science::PD Science: general issues
    Language: English
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  • 10
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    Environmental Democracy at the Global Level: Rights and Duties for a New Citizenship (2021)
    De Gruyter
    Details
    Publication Date: 2023-12-20
    Description: Giulia Parola’s Environmental Democracy at the Global Level: Rights and Duties for a New Citizenship can be seen as a manifesto that is both traditional and revolutionary at the same time. It calls for the construction of a new civilisation centred on the environment, while drawing on the traditional notions of democratic government. It adopts an approach that is focused on the power of individuals rather than governments, as ways to protect and improve the environment. It proposes that environmental rights and ecological duties are self-evident and inalienable, and should be treated as the cornerstones of a new democracy. Parola’s book is a thought provoking and intriguing work that will be of interest to scholars of environmental studies as well as to legal practitioners and non-specialists. Giulia Parola has studied Environmental Law at the University of Torino, at the University of René Descartes in Paris, (where she obtained PhD in Public Law) and at the University of Iceland ( LLM in Natural Resources Law and International Environmental Law). In 2011, she was appointed by the University of Laval (Canada, Quebec) as a researcher and a lecturer in Environmental Law.
    Keywords: GE1-350 ; K ; International Law ; Materials Science ; Industrial Chemistry ; Law ; Comparative Law ; Foreign Law ; Environment ; Natural Sciences ; German Civil Code ; Pollution Control ; bic Book Industry Communication::K Economics, finance, business & management::KC Economics::KCN Environmental economics
    Language: English
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  • 11
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    Aerodynamics (2021)
    IntechOpen | IntechOpen
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    Publication Date: 2024-04-11
    Description: Aerodynamics, the study of air motion around solid objects, allows us to understand and measure the dominating forces acting on aircrafts, buildings, bridges, automobiles, and other structures. The forces that result in an aircraft overcoming gravity and drag are called thrust and lift. Various parameters such as geometrical configurations of objects, as well as physical properties of air, which may be functions of position and time, affect those forces. This book covers some of the latest studies regarding the application of the principles of aerodynamics to the design of many different engineered objects. This book will be of interest to mechanical and aerospace engineering students, academics, and researchers who are looking for new insights into this fascinating branch of fluid mechanics.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Language: English
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  • 12
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    Disposable Bioprocessing Systems (2021)
    Taylor & Francis | CRC Press
    Details
    Publication Date: 2024-03-31
    Description: Because of many misconceptions, the biological drug manufacturing industry does not fully utilize disposable components, despite their wide availability. These misconceptions include concerns for the quality of materials, running costs, scalability, the level of automation possible, and the training of staff needed to include these components in existing bioprocessing systems. Not fully realizing the long-term benefits, many manufacturers are unwilling to discard investments made in fixed equipment and traditional stainless steel systems. Regulatory and environmental concerns, however, will eventually compel manufacturers to adopt disposable systems. Making a strong case for disposables, Disposable Bioprocessing Systems demonstrates the true potential of these systems. Written by a researcher and professor with hands-on experience in designing, establishing, and validating biological manufacturing facilities worldwide, and creating model facilities using maximum disposable technology, this book is the first comprehensive introduction to understanding disposable systems. It gives an overview of the current state of the disposable bioprocessing industry, resolves all controversial issues, and guides readers in choosing disposable components that meet their needs. An important chapter on safety addresses facts and myths about the use of plastics and elastomers—including the issue of leaching—and how to ensure regulatory compliance. Helping readers understand their choices, the book describes the equipment and systems available to prepare the starting materials for the manufacturing of biological drugs—from disposable containers to filters. The author also discusses costs, regulations, and concerns about waste disposal, and shares his predictions for the future of the disposable bioprocessing industry. A practical manual for those interested in the transition to disposable systems, this book will also interest students of bioprocessing. It offers a timely view of disposable bioprocessing technology as a "game changer" that will facilitate developing new drugs and conducting research in the emerging field of stem cells and gene therapy.
    Keywords: Biotechnology ; Pharmaceutical Science ; Industrial Chemistry ; PHARMACEUTICAL ; BIOSCIENCE ; CHEMLIB ; SCI-TECH ; BIOMEDICALSCIENCE ; CHEMICALENGINEERING ; STM ; bags ; bioreactors ; cleaning ; disposal ; downstream ; single ; stainless ; steel ; use ; validation ; thema EDItEUR::M Medicine and Nursing::MF Pre-clinical medicine: basic sciences ; thema EDItEUR::M Medicine and Nursing::MK Medical specialties, branches of medicine::MKG Pharmacology ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering ; thema EDItEUR::M Medicine and Nursing::MQ Nursing and ancillary services::MQW Biomedical engineering
    Language: English
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  • 13
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    Applied Aerodynamics (2021)
    IntechOpen | IntechOpen
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    Publication Date: 2024-04-11
    Description: Aerodynamics, from a modern point of view, is a branch of physics that study physical laws and their applications, regarding the displacement of a body into a fluid, such concept could be applied to any body moving in a fluid at rest or any fluid moving around a body at rest. This Book covers a small part of the numerous cases of stationary and non stationary aerodynamics; wave generation and propagation; wind energy; flow control techniques and, also, sports aerodynamics. It's not an undergraduate text but is thought to be useful for those teachers and/or researchers which work in the several branches of applied aerodynamics and/or applied fluid dynamics, from experiments procedures to computational methods.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Language: English
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  • 14
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    Wind Tunnel Designs and Their Diverse Engineering Applications (2021)
    IntechOpen | IntechOpen
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    Publication Date: 2024-04-11
    Description: This book is intended to be a valuable addition to students, engineers, scientists, industrialists, consultants and others providing greater insight into wind tunnel designs and their enormous research potential. It is a compilation of works from world experts on subsonic and supersonic wind tunnel designs, applicable to a diverse range of disciplines. The book is organised in two sections. The first section comprises of three chapters on various aspects of stationary and portable subsonic wind tunnel designs, followed by one chapter on supersonic wind tunnel and the final chapter discusses a method to address unsteadiness effects of fan blade rotation. The second section contains four chapters regarding wind tunnel applications across a multitude of engineering fields including civil, mechanical, chemical and environmental engineering.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Language: English
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  • 15
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    Low Reynolds Number (2021)
    IntechOpen | IntechOpen
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    Publication Date: 2024-04-11
    Description: This book reports the latest development and trends in the low Re number aerodynamics, transition from laminar to turbulence, unsteady low Reynolds number flows, experimental studies, numerical transition modelling, control of low Re number flows, and MAV wing aerodynamics. The contributors to each chapter are fluid mechanics and aerodynamics scientists and engineers with strong expertise in their respective fields. As a whole, the studies presented here reveal important new directions toward the realization of applications of MAV and wind turbine blades.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Language: English
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  • 16
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    Advances in Spacecraft Attitude Control (2021)
    IntechOpen
    Details
    Publication Date: 2024-04-04
    Description: Spacecraft attitude maneuvers comply with Euler's moment equations, a set of three nonlinear, coupled differential equations. Nonlinearities complicate the mathematical treatment of the seemingly simple action of rotating, and these complications lead to a robust lineage of research. This book is meant for basic scientifically inclined readers, and commences with a chapter on the basics of spaceflight and leverages this remediation to reveal very advanced topics to new spaceflight enthusiasts. The topics learned from reading this text will prepare students and faculties to investigate interesting spaceflight problems in an era where cube satellites have made such investigations attainable by even small universities. It is the fondest hope of the editor and authors that readers enjoy this book.
    Keywords: Science ; Mechanics ; Aerodynamics ; bic Book Industry Communication::P Mathematics & science::PH Physics::PHD Classical mechanics::PHDF Fluid mechanics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHD Classical mechanics::PHDF Physics: Fluid mechanics
    Language: English
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  • 17
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    Unit Operations of Particulate Solids (2021)
    Taylor & Francis | CRC Press
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    Publication Date: 2024-04-11
    Description: Suitable for practicing engineers and engineers in training, this book covers the most important operations involving particulate solids. Through clear explanations of theoretical principles and practical laboratory exercises, the text provides an understanding of the behavior of powders and pulverized systems. It also helps readers develop skills for operating, optimizing, and innovating particle processing technologies and machinery in order to carry out industrial operations. The author explores common bulk solids processing operations, including milling, agglomeration, fluidization, mixing, and solid-fluid separation.
    Keywords: Industrial Chemistry ; Food Chemistry ; FOOD ; CHEMLIB ; SCI-TECH ; CHEMICALENGINEERING ; CHEMISTRY ; STM ; bed ; distribution ; fluidized ; industry ; mass ; material ; particle-size ; processing ; technology ; transfer ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering::TDCT Food and beverage technology ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
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  • 18
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    Wind Tunnels (2021)
    IntechOpen | IntechOpen
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    Publication Date: 2024-04-11
    Description: Although great advances in computational methods have been made in recent years, wind tunnel tests remain essential for obtaining the full range of data required to guide detailed design decisions for various practical engineering problems. This book collects original and innovative research studies on recent applications in wind tunnel tests, exhibiting various investigation directions and providing a bird’s eye view on this broad subject area. It is composed of seven chapters that have been grouped in two major parts. The first part of the book (chapters 1–4) deals with wind tunnel technologies and devices. The second part (chapters 5–7) deals with the latest applications of wind tunnel testing. The text is addressed not only to researchers but also to professional engineers, engineering lecturers, and students seeking to gain better understanding of the current status of wind tunnels.　Through its seven chapters, the reader will have an access to a wide range of works related to wind tunnel testing.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Language: English
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  • 19
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    Chapter 13 Modelling Seismic Wave Propagation for Geophysical Imaging (2021)
    InTechOpen
    Details
    Publication Date: 2024-04-04
    Description: The Earth is an heterogeneous complex media from the mineral composition scale (10−6m) to the global scale ( 106m). The reconstruction of its structure is a quite challenging problem because sampling methodologies are mainly indirect as potential methods (Günther et al., 2006; Rücker et al., 2006), diffusive methods (Cognon, 1971; Druskin & Knizhnerman, 1988; Goldman & Stover, 1983; Hohmann, 1988; Kuo & Cho, 1980; Oristaglio & Hohmann, 1984) or propagation methods (Alterman & Karal, 1968; Bolt & Smith, 1976; Dablain, 1986; Kelly et al., 1976; Levander, 1988; Marfurt, 1984; Virieux, 1986). Seismic waves belong to the last category. We shall concentrate in this chapter on the forward problem which will be at the heart of any inverse problem for imaging the Earth. The forward problem is dedicated to the estimation of seismic wavefields when one knows the medium properties while the inverse problem is devoted to the estimation of medium properties from recorded seismic wavefields.
    Keywords: seismic wave ; geophysical imaging ; seismic wave ; geophysical imaging ; Boundary value problem ; Finite element method ; Free surface ; Frequency domain ; Seismology ; Time domain ; Velocity ; thema EDItEUR::P Mathematics and Science::PD Science: general issues
    Language: English
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  • 20
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    Advances in Spacecraft Attitude Control (2021)
    IntechOpen | IntechOpen
    Details
    Publication Date: 2024-04-11
    Description: Spacecraft attitude maneuvers comply with Euler's moment equations, a set of three nonlinear, coupled differential equations. Nonlinearities complicate the mathematical treatment of the seemingly simple action of rotating, and these complications lead to a robust lineage of research. This book is meant for basic scientifically inclined readers, and commences with a chapter on the basics of spaceflight and leverages this remediation to reveal very advanced topics to new spaceflight enthusiasts. The topics learned from reading this text will prepare students and faculties to investigate interesting spaceflight problems in an era where cube satellites have made such investigations attainable by even small universities. It is the fondest hope of the editor and authors that readers enjoy this book.
    Keywords: Aerodynamics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Language: English
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  • 21
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    Understanding Micropolar Theory in the Earth Sciences II: The Seismic Moment Tensor (2021)
    Springer International Publishing
    Details
    Publication Date: 2023-06-12
    Description: Seismic events produced by block rotations about vertical axis occur in many geodynamic contexts. In this study, we show that these rotations can be accounted for using the proper theory, namely micropolar theory, and a new asymmetric moment tensor can be derived. We then apply this new theory to the Kaikōura earthquake (2016/11/14), Mw 7.8, one of the most complex earthquakes ever recorded with modern instrumental techniques. Using advanced numerical techniques, we compute synthetic seismograms including a full asymmetric moment tensor and we show that it induces measurable differences in the waveforms proving that seismic data can record the effects of the block rotations observed in the field. Therefore, the theory developed in this work provides a full framework for future dynamic source inversions of asymmetric moment tensors.
    Description: Westfälische Wilhelms-Universität Münster (1056)
    Keywords: ddc:551.22 ; Seismology ; asymmetric moment tensor ; micropolar theory ; Kaikōura earthquake
    Language: English
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  • 22
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    Imaging seismic wave-fields with AlpArray and neighboring European networks (2021)
    Springer Berlin Heidelberg
    Details
    Publication Date: 2024-02-28
    Description: The AlpArray experiment and the deployment of Swath-D together with the dense permanent network in Italy allow for detailed imaging of the spatio-temporal imaging complexity of seismic wave-fields within the greater Alpine region. The distance of any point within the area to the nearest station is less than 30 km, resulting in an average inter-station distance of about 45 km. With a much denser deployment in a smaller region of the Alps (320 km in length and 140 km wide), the Swath-D network possesses an average inter-station distance of about 15 km. We show that seismogram sections with a spatial sampling of less than 5 km can be obtained using recordings of these regional arrays for just a single event. Multiply reflected body waves can be observed for up to 2 h after source time. In addition, we provide and describe animations of long-period seismic wave-fields using recordings of about 1300–1600 broadband stations for six representative earthquakes. These illustrate the considerable spatio-temporal variability of the wave-field’s properties at a high lateral resolution. Within denser station distributions like those provided by Swath-D, even shorter period body and surface wave features can be recovered. The decrease of the horizontal wavelength from P to S to surface waves, deviations from spherically symmetric wavefronts, and the capability to detect multi-orbit arrivals are demonstrated qualitatively by the presented wave-field animations, which are a valuable tool for educational, quality control, and research purposes. We note that the information content of the acquired datasets can only be adequately explored by application of appropriate quantitative methods accounting for the considerable complexity of the seismic wave-fields as revealed by the now available station configuration.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: Christian-Albrechts-Universität zu Kiel (3094)
    Keywords: ddc:551.22 ; Seismology ; Wave-fields ; Animations ; Alps ; AlpArray ; Swath-D
    Language: English
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  • 23
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    Seismological profile across Longmenshan Fault - LONGMEN-P (2018-2020) (2021)
    GFZ Data Services
    Details
    Publication Date: 2024-02-23
    Description: Abstract
    Description: The main aim of this project is to investigate the crustal and mantle structure beneath the Longmenshan fault zone in China, based on a very dense passive seismology profile. The Longmenshan fault zone hosted the Wenchuan earthquake of May 2008 with a magnitude (Mw) of 7.9 and the Lushan earthquake of June 2013 with a magnitude (Mw) of 6.6. It is planned to mainly use the receiver-function method, to investigate the crustal and mantle structure beneath the Longmenshan fault zone. Waveform data are available from the GEOFON data center, under network code 4O, and are embargoed until February 2024.
    Keywords: Broadband seismic waveforms ; Seismology ; temporary local seismic experiment ; Earthquake ; Receiver functions ; Crustal and mantle structure ; China ; Monitoring system ; EARTH SCIENCE 〉 SOLID EARTH ; In Situ/Laboratory Instruments 〉 Magnetic/Motion Sensors 〉 Seismometers ; In Situ Land-based Platforms 〉 GEOPHYSICAL STATIONS/NETWORKS ; In Situ Land-based Platforms 〉 GEOPHYSICAL STATIONS/NETWORKS 〉 SEISMOLOGICAL STATIONS
    Type: Dataset , Seismic Network
    Format: ~1T
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    DATA GFZ
  • 24
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    Dataset of the 3P seismic network at the Theistareykir geothermal area, Iceland, 2017-2021 (2021)
    GFZ Data Services
    Details
    Publication Date: 2024-05-21
    Description: Abstract
    Description: Continuous passive seismic monitoring is carried out between September 2017 and December 2021 around the Theistareykir geothermal area located at the intersection between the active Northern Rift Zone and the active Tjörnes Fracture Zone in NE Iceland. This experiment, in addition to an extensive gravimetric monitoring survey, was conducted in the framework of the MicroGraviMoTiS project for a better understanding of the structures and behavior of the local geothermal system under exploitation and for further development of local and regional geothermal resources. 14 broadband stations (Trillium C-120s) recording at 200 Hz comprise the temporary network, that is installed to complement stations of the national seismological network of IMO and stations of Landsvirkjun, the National Power Company of Iceland. The stations were placed in and around the producing zone to primarily retrieve local natural and/or induced seismicity associated to the injection and production operations. The retrieved seismic data is also used for obtaining a representative 1D velocity model of the region, for computing a seismic ambient noise tomography, and for monitoring the system using coda wave interferometry techniques. Funding for this project is provided by the German Federal Ministry for Education and Research (MicroGraviMoTiS , BMBF, grant: 03G0858A), the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences and Landsvirkjun. Waveform data are available from the GEOFON data center, under network code 3P, and are embargoed until December 2025.
    Keywords: Broadband seismic waveforms ; Seismology ; temporary local seismic experiment ; Monitoring system ; EARTH SCIENCE 〉 SOLID EARTH ; In Situ/Laboratory Instruments 〉 Magnetic/Motion Sensors 〉 Seismometers ; In Situ Land-based Platforms 〉 GEOPHYSICAL STATIONS/NETWORKS ; In Situ Land-based Platforms 〉 GEOPHYSICAL STATIONS/NETWORKS 〉 SEISMOLOGICAL STATIONS ; Passive seismic ; Seismometers ; Velocity ; MiniSEED ; GIPP ; MESI ; Volcano
    Type: Dataset , Seismic Network
    Format: 783GB
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  • 25
    Electronic Resource
    Electronic Resource
    Eine Verbesserung von Alsops Methode zur Bestimmung der Reflexions- und Transmissionskoeffizienten von Oberflächenwellen (1979)
    Springer
    Pure and applied geophysics 117 (1979), S. 1045-1049 
    Details
    ISSN: 1420-9136
    Keywords: Seismology ; Surface waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary Alsop's method (1966) for the non-normal passage of surface waves through a vertical discontinuity is improved by using a new functional to be made stationary on the plane of discontinuity. The modified functional has the dimension of an energy flux and is characterized by the discontinuous surface wave displacements and stresses on the vertical discontinuity. Model calculations which were carried out for SV-waves and Love waves show that the new version of Alsop's method yields in all respects more consistent results than the old one.
    Notes: Zusammenfassung Die Methode von Alsop (1966) für den Durchgang von schräg einfallenden Oberflächenwellen durch eine vertikale Diskontinuität wird durch Verwendung eines neuen Funktionals, das auf der Diskontinuitätsfläche stationär sein soll, verbessert Das modifizierte Funktional hat die Dimension eines Energieflusses und wird durch diejenige Spannungs- und Verschiebungsdiskontinuität charakterisiert, die durch das Oberflächenwellenfeld auf der Diskontinuitätsfläche erzeugt wird. Modellrechnungen für SV-Wellen und Lovewellen zeigen, daß die neue Version von Alsoos Verfahren in jeder Hinsicht konsistentere Ergebnisse als die bisherige liefert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876084
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  • 26
    Electronic Resource
    Electronic Resource
    Bicyclo[2.1.1]hexane aus Tricyclo[3.1.0.02,6]hexanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2012-2021 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bicyclo[2.1.1]hexanes from Tricyclo[3.1.0.02,6]hexanesThe novel tricyclo[3.1.0.02,6]hexane derivatives 3 and 4, being fused with a fife- and a sixmembered ring respectively, are prepared from benzvalene in several steps. They and their lower homologues 1 and 2, having a three- and fourmembered ring respectively, add thiophenol under conditions of a radical reaction to form smoothly one cyclobutylphenyl thioether (16-19) in each case. Therefrom the parent hydrocarbons (5-8) which contain the bicyclo[2.1.1]hexane skeleton, are obtained by means of reduction with lithium in ethylamine.
    Notes: Ausgehend von Benzvalen werden in mehreren Stufen die neuen Tricyclo[3.1.0.02,6]hexan-Derivate 3 und 4 mit anelliertem Fünf- bzw. Sechsring dargestellt. Sie und ihre niedrigeren Homologen 1 und 2 mit Drei- bzw. Vierring nehmen unter Bedingungen einer Radikalreaktion Thiophenol auf, wobei glatt jeweils ein Cyclobutylphenylthioether (16-19) gebildet wird. Mit Lithium in Ethylamin sind aus 16-19 die tricyclischen Stammkohlenwasserstoffe mit dem Bicyclo[2.1.1 ]hexan-Gerüst (5-8) erhältlich.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120611
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  • 27
    Electronic Resource
    Electronic Resource
    Der Einfluß anellierter Ringe auf die 13C-NMR-chemischen Verschiebungen von Tricyclo[3.1.0.02,6]hexan- und Bicyclo[2.1.1]hexan-Derivaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2022-2027 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Influence of Fused Rings on the 13C Shieldings of Tricyclo[3.1.0.02,6]hexane and Bicyclo[2.1.1]hexane DerivativesThe 13C shieldings of the tricyclo[3.1.0.02,6]hexane derivatives 2-5 and of the bicyclo[2.1.1]-hexane derivatives 7-10 and 12-15 show a strong dependence on the size of the fused rings. Especially the γ-anti-effects, which cause downfield shifts, and the γ-syn-effects of these rings, which result in upfield shifts, are subject to unexpected variations.
    Notes: Die 13C-chemischen Verschiebungen der Tricyclo[3.1.0.02,6]hexan-Derivate 2-5 und der Bicyclo[2.1.1]hexan-Derivate 7-10 und 12-15 zeigen eine starke Abhängigkeit von der Größe der anellierten Ringe. Insbesondere die nach tieferem Feld gerichteten γ-anti-Effekte und die nach höherem Feld gerichteten γ-syn-Effekte dieser Ringe unterliegen unerwarteten Variationen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120612
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  • 28
    Electronic Resource
    Electronic Resource
    Reaktionen an Indolderivaten, XXXIX. Stereoselektive Totalsynthese von Eburnamonin, Eburnamin und Eburnamenin (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1902-1912 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XXXIX. A Stereoselective Synthesis of Eburnamonine, Eburnamine, and EburnamenineStudies on the five-membered lactams 1 and 2 disclose a stereoselective access to eburnamonin-19-one (22). This substance is easily transformed into eburnamonine (25), eburnamine (30), and eburnamenine.
    Notes: Das Studium der 5-Ring-Lactame 1 und 2 eröffnet einen stereoselektiven Zugang zum Eburnamonin-19-on (22). Diese Substanz läßt sich auf einfache Weise in die drei Alkaloide Eburnamonin (25), Eburnamin (30) und Ehurnamenin überführen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120541
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  • 29
    Electronic Resource
    Electronic Resource
    En-Reaktionen mit Cyanthioformaniliden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1916-1918 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ene Reactions with CyanothioformanilidesCyanothioformanilides 3 react with methylenecyclohexane (1) and β-pinene (2) in boiling toluene to yield the adducts 4 and 5, resp., according to the mechanistic scheme of an ene reaction.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120543
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  • 30
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120601
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  • 31
    Electronic Resource
    Electronic Resource
    Synthesis of new chiral hydrocarbons (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1919-1922 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthese von neuen chiralen KohlenwasserstoffenUnsymmetrisches Anheften einer aliphatischen (CH2)n-Brücke an ein an sich achirales aromatisches System führt zu starren chiralen Kohlenwasserstoffen des Typs 2; die Enantiomeren 2 a konnten mit Hilfe von TAPA angereichert werden. Die Racemisierungskinetik wurde polarimetrisch bestimmt: ΔG≠20 = 93.6 kJ · mol-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120544
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  • 32
    Electronic Resource
    Electronic Resource
    Pheromone, XXIV. Notiz zur Synthese der Sexuallockstoffe (Z)-7-Dodecenylacetat und (Z)-7-Tetradecenylacetat (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1923-1925 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pheromones, XXIV. Synthesis of the Sex Attractants (Z)-7-Dodecenyl Acetate and (Z)-7-Tetradecenyl Acetate(Z)-7-Dodecenyl acetate, the female sex pheromone of the Noctuid moth Trichoplusia ni, and (Z)-7-tetradecenyl acetate, the sex attractant of Amathes c-nigrum (Lepidoptera), are prepared by stereoselective Wittig olefination using the „silazide“ -technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120545
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  • 33
    Electronic Resource
    Electronic Resource
    Dynamische NMR- Untersuchungen an (Di-tert-butylamino)arsanen und -stibanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1927-1933 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dynamic NMR Studies of (Di-tert-butylamino)arsanes and -stibanesThe reaction of LiN[C(CH3)3]2 with AsX3 (X = F → Br). (CH3)3CAsCl2 and SbCl3 yields the di-tert-butylamino)arsanes 1a-c, 2 and dichloro(di-tert-butylamino)stibane (1d). LiN(CR3)-(SiR3), R=CH3and 1a-c form 3. The El — N torsional barriers of these compounds (measured by temperature dependent 1H-NMR spectroscopy) are compared with those of the (diisopropylamino)arsanes 4. and other related compounds. The influence of the N and El ligands with respect to the El — N torsional barrier is discussed. Thermolysis of 3c affords the di-tert-butylaminyl radical.
    Notes: Durch Umsetzung von LiN[C(CH3)3]2 mit AsX3 (X = F → Br), (CH3)3CAsCl2 und SbCl3 erhält man die (Di-tert-butylamino)arsane 1a-c und 2 sowie Dichlor(di-tert-butylamino)stiban reagieren mit LiN(CR3)(SiR3), R=CH3 zu 3 weiter. Die durch temperaturabhängige 1 H-NMR-Messungen ermittelten El- N-Rotationsbarrieren dieser Verbindungen werden hinsichtlich des Ligandeneinflusses am N- El - Atom mit den (Diisopropylamino)arsanen 4. und verwandten Molekülen verglichen. 3c. ergibt bei der Thermolyse das Di-tert-butylaminyl-Radikal.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120602
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  • 34
    Electronic Resource
    Electronic Resource
    Isocyanidkomplexe, I. Isocyanphosphane und -arsane als Komplexliganden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1934-1940 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isocyanide Complexes, I. Isocyanophosphanes and -arsanes as Ligands of ComplexesThe reaction of K[CpMn(CO)2CN] (Cp = η-C5H5) with PR2Cl (R=C2H5, OC2H5, C6H5) and As(C6H5)2Cl yields the complexes CpMn(CO)2CNPR2 (3a - c) and CpMn(CO)2CNAsPh2 (3d) with C-coordinated isocyanophosphanes and -arsanes. In the reaction of CpMn(CO)2CNPPh2 with CpMn(CO)2 THF or of K[CpMn(CO)2CN] with CpMn(CO)2PPh2Cl a complex with an isocyanophosphane bridge, {CpMn(CO)2}2(CNPPh2) (4), is obtained. The IR, NMR, and mass spectra of the compounds 3a-d and 4 are discussed.
    Notes: Bei der Umsetzung von K[CpMn(CO)2CN] (Cp = η-C5H5) mit PR2Cl (R=C2H5, OC2H5, C6H5) und As(C6H5)2Cl entstehen die Komplexe CpMn(CO)2CNPR2 (3 a - c) und CpMn(CO)2CNAsPh2 (3d) mit C-gebundenen Isocyanphosphanen und -arsanen. Durch Reaktion von CpMn(CO)2CNPPh2 (3c) mit CpMn(CO)2 THF bzw. von K[CpMn(CO)2]CN mit CpMn(CO)2PPh2Cl erhält man den Komplex {CpMn(CO)2}2(CNPPh2) (4) mit einer Isocyanphosphan-Brücke. Die IR-, NMR- und Massenspektren der Verbindungen 3a-d und 4 werden diskutiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120603
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  • 35
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    Barrieren der behinderten Rotation um die N-glycosidische Bindung, IV. 1-(β-D-Ribofuranosyl)isocyanursäuren (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1941-1947 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Barriers to Hindered Rotation Around the N-Glycosidic Bond, IV. 1-(βD-Ribofuranosyl) isocyanuric AcidsThe β-ribofuranosyl nucleosides 5a-c and 6b, c are synthesized. The temperature dependency of the 1H- and 13C-NMR spectra can only be interpreted as hindered rotation around the N-glycosidic bond2). The Gibbs activation energies (43-46 kJmol-1) are independent of acetylation of the OH groups of the furanose ring or restriction of its flexibility through formation of a 2′,3′-isopropylidene derivative, and are considerably lower than the corresponding data (about 69 kJmol-1) of the glucopyranosyl nucleosides 7b, c. The activation entropies are small. The results are interpreted.
    Notes: Es werden Synthesen der β-Ribofuranosylnucleoside 5a-c und 6b, c beschrieben. Die Temperaturabhängigkeiten der 1H-und 13C-NMR-Spektren lassen sich nur als Folge behinderter Rotation um die N-glycosidische Bindung deuten2) Die Gibbsschen Aktivierungsenergien (43-46 kJmol-1) sind unabhängig von einer Acetylierung der OH-Gruppen des Furanoseringes oder einer Einschränkung von dessen Flexibilität durch Bildung eines 2′,3′-Isopropylidenderivates und liegen erheblich tiefer als die entsprechenden Werte (um 69 kJmol-1) der Glucopyranosylnucleoside 7b, c. Die Aktivierungsentropien sind gering. Die Befunde werden gedeutet.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120604
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  • 36
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    Synthesen von α-Bromisothiocyanaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1948-1955 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of α-BromoisothiocyanatesSecondary isothiocyanates (1j-q) and primary isothiocyanates R—CH2 - NCS with an activating group R (1f, g) react with N-bromosuccinimide (NBS) to form α-bromoisothiocyanates 2 in high yields. The not activated primary isothiocyanate 1c slowly forms the stable α,α-dibromoisothiocyanate 10. In the presence of β-hydrogens some of the α-bromoisothiocyanates 2 eliminate HBr spontaneously, and secondary products may be formed. The α-bromination of isothiocyanates is a radical reaction following a Goldfinger mechanism.
    Notes: Sekundäre Isothiocyanate (1j-q) und primäre Isothiocyanate R-CH2 - NCS mit einer aktivierenden Gruppe R (1f, g) lassen sich mit N-Bromsuccinimid (NBS) in hohen Ausbeuten zu den α-Bromisothiocyanaten 2 bromieren. Das nicht aktivierte Isothiocyanat 1c reagiert langsam zum stabilen α,α-Dibromisothiocyanat 10. Bei Anwesenheit von β-Wasserstoffatomen spalten die α-Bromisothiocyanate 2 zum Teil spontan HBr ab, und es entstehen Folgeprodukte. Die α-Bromierung der Isothiocyanate erfolgt radikalisch nach einem Goldfinger-Mechanismus.
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    Reaktionen von α-Bromisothiocyanaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1956-1972 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of α-Bromoisothiocyanatesα-Bromoisothiocyanates 11.2) with a hydrogen in β-position eliminate HBr to form vinyl isothiocyanates (products 2, 3, 5). Water hydrolyzes 1 to carbonyl compounds (7a). Hard nucleophiles attack 1 at the α-C-atom with substitution of bromine (products 8-12), but soft nucleophiles add to the C-atom of the isothiocyanato group (products 14, 19). Compounds 1 react with bifunctional nucleophiles to heterocycles (e. g. products 16, 21). The chemical properties of the classes of compounds, part of which are new, e. g. the geminal diisothiocyanates 12, are examined. The alkylidene thiourea 14f shows hindered rotation around the amide-CS—N bond (ΔG≠394 = 82.8 kJmol-1) and around the C=N double bond (ΔG≠244 = 52.9 kJmol-1).
    Notes: α-Bromisothiocyanate 1 mit einem β-Wasserstoff spalten HBr zu Vinylisothiocyanaten ab (Produkte 2, 3, 5). Wasser hydrolysiert 1 zu Carbonylverbindungen (7a). Harte Nucleophile greifen 1 am α-C-Atom unter Substitution des Broms an (Produkte 8-12), weiche Nucleophile lagern sich dagegen an das C-Atom der Isothiocyanatgruppe an (Produkte 14, 19). Verbindungen 1 reagieren mit bifunktionellen Nucleophilen zu Heterocyclen (z. B. Produkte 16, 21). Die chemischen Eigenschaften der z. T. neuen Verbindungsklassen, z. B. der geminalen Diisothiocyanate 12, werden untersucht. Der Alkylidenthioharnstoff 14f zeigt behinderte Rotation um die Amid Cs—N-Bindung (ΔG≠394 = 82.8 kJmol-1) und um die C=N-Doppelbindung (ΔG≠244 = 52.9 kJmol-1).
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    Die Kristallstruktur von (η3-Allyl)dicarbonyl(triphenyl-phosphan)cobalt und sein dynamisches Verhalten in Lösung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1973-1980 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structure and the Fluxional Behaviour in Solution of (η3-Allyl)dicarbonyl(triphenyl-phosphane)cobalt[Co(η3-C3H5)(CO)2PPh3] (1) crystallizes in the triclinic space group P1 with two molecules per unit cell. The crystal structure was solved and refined with X-ray diffraction data (R = 0.031, 2046 observed reflections). The cobalt atom has a distorted square pyramidal coordination with the formally bidentate η3-allyl ligand, the phosphane, and one carbonyl in the basal positions. According to the NMR spectra at temperatures down to 135 K, in solution there exists a fluxional equilibrium with the η3-allyl ligand oscillating between two enantiomeric positions.
    Notes: [Co(η3-C3H5)(CO)2PPh3] (1) kristallisiert triklin in der Raumgruppe P1 mit zwei Molekülen pro Elementarzelle. Die Kristallstruktur wurde mit Röntgenbeugungsdaten ermittelt und verfeinert (R = 0.031, 2046 beobachtete Reflexe). Das Cobaltatom ist verzerrt quadratisch-pyramidal koordiniert, mit dem formal zweizähnigen η3-Allylliganden, dem Phosphan und einem Carbonylliganden in der Pyramidenbasis. Nach den NMR-Spektren bei Temperaturen hinab bis 135 K liegt in Lösung ein dynamisches Gleichgewicht vor, bei dem die η3-Allylgruppe zwischen zwei enantiomeren Positionen fluktuiert.
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    Hydrazidine, III. Synthese von 1,2,4,5-Tetrazino [3,2-a]isoindolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1981-1990 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrazidines, III. Synthesis of 1,2,4,5-Tetrazino[3,2-a]isoindolesReaction of acetohydrazide hydrazone hydrochloride (1) with phthalaldehydic acid (5) yields 3-methyl-1,10b-dihydro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (8), which affords 1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (9a) by mild oxidation. 9a is also obtained by the reaction of 1 with the phthalic acid derivatives 6a, 7a, and 7b. Starting with 9a, the 1,2,4,5-tetrazino[3,2-a]isoindoles 12-15 are synthesized. Interaction of 1 and 3-nitrophthalic anhydride (6b) yields two isomeric nitro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-ones (9b,c). Oxidation of 9a or b with KMnO4 in methanol affords the 1,2,4,5-tetrazino 17a, b. Mild Oxidation of 9a with KMnO4 in water/trichloromethane yields a dimer (20), which dissociates in nitromethane into the radical 19.
    Notes: Durch Reaktion von Acetohydrazid-hydrazon-hydrochlorid (1) mit Phthaladehydsäure (5) wird 3-Methyl-1, 10b-dihydro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-on (8) erhalten das durch milde Oxidation in 3-Methyl-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-on (9a) übergeführt wird. 9a entsteht auch aus 1 und den Phthalsäurederivaten 6a, 7a und 7b. Ausgehend von 9a werden die 1,2,4,5-Tetrazino[3,2-a]isoindole 12-15 synthetisiert. Aus 1 und 3-Nitrophthalsäureanhydrid (6b) werden zwei isomere Nitro-1,2,4,5-tetrazino[3,2-a]isoindol-6(4H)-one (9b, c) erhalten. Oxidation von 9a oder b mit KMnO 4 in Methanol ergibt die 1,2,4,5-Tetrazine 17a, b. Vorsichtige Oxidation von 9a mit KmnO4 in Wasser/Chloroform ergibt ein Dimeres (20), das in Nitromethan in das Radikal 19 dissoziiert.
    Additional Material: 2 Ill.
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    Stereochemie der Metall-Metall-Bindung. Strukturvergleich der Komplexe Cr2(CO)8(AsMe2)2, CrFe(CO)7(AsMe2)2 und Fe2(CO)6(AsMe2)2 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1991-1998 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Metal-Metal Bond. Structural Comparison of the Complexes Cr2(CO)8(AsMe2)2, CrFe(CO)7(AsMe2)2, and Fe2(CO)6(AsMe2)2The molecular structures of the new complexes CFer2(CO)8(AsMe2)2 (1) and CrFe(CO)7(AsMe2)2 (2) were determined crystallographically, that of Fe2(CO)6(AsMe2)2 (3) was redetermined. In all three compounds the metal-metal bond lengths are determined by the goemetrical requirements of the ligands. The fact that the M2As2 framework is planar in 1 and strongly folded in 2 and 3 can also be explained by the steric demands of the ligands. Aspects of the fluxionality of these complexes are discussed.
    Notes: Die Molekülstrukturen der neuen Komplexe Cr2(CO)8(AsMe2)2 (1) und CrFe(CO)7(AsMe2)2 (2) wurden kristallographisch ermittelt, die von Fe2(CO)6(AsMe2)2 (3) wurde neu bestimmt. In allen drei Verbindungen sind die Metall-Metall-Bindungslängen durch die geometrischen Ansprüche der Liganden festgelegt. Auch die Tatsache, daß das M2As2-Gerüst in 1 eben und in 2 und 3 jeweils stark gefaltet ist, läßt sich auf den Raumbedarf der Liganden zurückführen. Aspekte der Fluktuation dieser Komplexe werden diskutiert.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120609
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    Untersuchungen an Stoffwechselprodukten von Mikroorganismen, XX. Die Konstitutionen der Pigmente vom Flexirubin-Typ aus Cytophaga johnsonae Cyjl (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1999-2011 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Metabolites of Microorganisms, XX. The Structures of the Flexirubin-type Pigments from Cytophaga johnsonae CyjlCytophaga johnsonae Cy jl produces more than 25 different flexirubin-type pigments (2 a-h, 3 a-h, 4 a-h, 5) besides lower concentrations of carotenoids. These pigments could be separated using HPLC. Their structures have been elucidated. 5 is the first known member in this class of bacterial pigments containing two chlorine atoms.
    Notes: Das Gleitende Bakterium Cytophaga johnsonae Cy jl produziert neben wenig Carotinoiden mehr als 25 verschiedene Pigmente vom Flexirubin-Typ (2a-h, 3a-h, 4a-h, 5), deren Trennung u.a. durch Hochdruckflüssigchromatographie gelang. Über die Konstitutionen dieser Pigmente wird berichtet. Mit 5 wurde erstmals in dieser Verbindungsklasse ein dichlorhaltiges Pigment aufgefunden.
    Additional Material: 7 Tab.
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    Proton Magnetic Resonance Investigation of Inversion at Tervalent Nitrogen, 6. Preparative Separations of Enantiomeric Diaziridines by Liquid Chromatography on Triacetylcellulose. Racemizations Monitored by Polarimetry and by 1H NMR (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2028-2038 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Protonenresonanz-Untersuchugen zur Inversion am dreibindigen Stickstoffatom, 6. Präparative Trennungen enantiomerer Diaziridine durch Flüssigkeits-Chromatographie an Triacetylcellulose. Verfolgung der Racemisierungen mittels Polarimetrie und 1H-NMREnantiomere Diaziridine ließen sich durch Chromatographie an Triacetylcellulose anreichern. (-)-2, (+)-4 und (-)-4 wurden fast rein erhalten, wobei die enantiomeren Reinheiten (Tab. 1) mittels 1H-NMR in Gegenwart optisch aktiver Zusätze bestimmt wurden. Dasselbe Verfahren wurde im Hinblick auf die Verfolgung von Racemisierungen (Tab.2) erprobt, welche mit höherer Genauigkeit außerdem mittels Polarimetrie studiert wurden. Die Schwellen der Stickstoff-Inversion, welche die trans-Diaziridine 2 und 4 in cis-Zwischenstufen überführt, werden mit bekannten ΔG≠-Werten verglichen.
    Notes: Enantiomeric diaziridines have been partially separated by chromatography on triacetlycellulose. (-)-2, (+)-4, and (-)-4 were obtained almost pure, enantiomeric purities (Table 1) being measured by 1H NMR in the presence of optically active additives. The same procedure was tested for monitoring racemizations (Table 2) which were also studied, with higher accuracy, by polarimetry. The barriers to nitrogen inversion, converting the trans-diaziridines 2and4into cis-intermediates, are compared with known ΔG≠ values.
    Additional Material: 2 Ill.
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    Darstellung, Schwingungsspektrum und Kristallstruktur des dimeren (Isopropylidenamino) dimethylindiums (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2039-2044 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation, Vibrational Spectrum, and Crystal Structure of Dimeric (Isopropylideneamino) dimethylindiumThe title compound [Me2C=N—InMe2]2 was prepared from N-chloro-2-propanimine and trimethylindium. Its IR and Raman spectra were assigned; together with the 1H-NMR spectrum and the mass spectrum a centrosymmetric molecular structure with a four-membered (InN)2 ring was deduced. This was confirmed by an X-ray structure determination, according to which there exist two dimeric molecules per unit cell in the space group P21/c. The structure was refined with 958 reflexions up to a residual index of R = 0.024.
    Notes: Die Titelverbindung [Me2C=N-InMe2]2 wurde aus N-Chlor-2-propanimin und Trimethylindium synthetisiert. Das IR-und Raman-Spektrum wurde zugeordnet; zusammen mit dem 1H-NMR- und dem Massenspektrum ergibt sich eine zentrosymmetrische Molekülstruktur mit einem (InN)2-Vierring. Dies wird durch die Röntgenstrukturbestimmung bestätigt, nach der eine Struktur mit zwei dimeren Molekülen pro Elementarzelle in der Raumgruppe P21/c vorliegt. Die Struktur wurde bis zu einem Übereinstimmungsindex von R = 0.024 für 958 Reflexe verfeinert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120614
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    Trimethylsilylcyanid als Umpolungsreagens, I. Nucleophile Acylierung von Alkylierungsmitteln mit aromatischen und heteroaromatischen Aldehyden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2045-2061 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylsilyl Cyanide  -  A Reagent for Umpolung, I. Nucleophilic Acylation of Alkylating Reagents with Aromatic and Heteroaromatic AldehydesThe readily accessible adducts 7 from (hetero)aromatic aldehydes and trimethylsilyl cyanide are deprotonated by lithium diisopropylamide. The so formed anions 8 react with alkyl halides, dialkyl sulfates and alkyl tosylates producing 19 with inversion and without interfering elimination. From 19 the protective group is removed under mild conditions and ketones 20 are produced mostly in 80-90% yield. The scope of the reaction sequence with respect to (hetero)aromatic aldehydes and alkylating agents is demonstrated. Lithium ions are shown to cooperate in the smooth substitution of tert-butyl iodide by 8. Within the given limits the described reaction sequence complements advantageously the known methods of nucleophilic acylation.
    Notes: Die aus (hetero)aromatischen Aldehyden und Trimethylsilylcyanid glatt zugänglichen Addukte 7 werden von Lithium-diisopropylamid zu den Anionen 8 deprotoniert, die ohne störende Eliminierung mit Alkylhalogeniden, Dialkylsulfaten und Alkyltosylaten unter Inversion zu 19 reagieren. Entfernung der Schutzgruppe aus 19 unter sehr milden Bedingungen liefert die Ketone 20 meist in Ausbeuten von 80-90%. Die Anwendungsbreite hinsichtlich der (hetero)aromatischen Aldehyde und der Alkylierungsmittel wird demonstriert. Für die glatte Substitution von tert-Butyliodid durch 8 wird Mitwirkung der Lithium-Ionen nachgewiesen. Im gesteckten Rahmen ergänzt diese nucleophile Acylierung die bekannten Methoden vorteilhaft.
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    Trimethylsilylcyanid als Umpolungsreagens, II. Nucleophile Acylierung von Aldehyden und Ketonen unter anionischer 1,4-O,O-Silylgruppenwanderung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2062-2067 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylsilyl Cyanide  -  A Reagent for Umpolung, II. Nucleophilic Acylation of Aldehydes and Ketones with Anionic 1,4-O,O-Silyl ShiftThe anion 9, derived from O-(trimethylsilyl) benzaldehyde-cyanohydrin (8), adds quantitatively to aldehydes and ketones. The primary adduct 11, which can be trapped as 12 after short reaction times, rearranges with 1,4-0,0-silyl shift. By subsequent cyanide elimination acyloin silyl ethers 14 are formed. Hydrolysis of 14 yields 80-90% of acyloins 15.
    Notes: Das Anion 9 des O-(Trimethylsilyl)benzaldehyd-cyanhydrins (8) addiert sich quantitativ an Aldehyde und Ketone. Das Primäraddukt 11, nach kurzer Reaktionszeit als 12 faßbar, lagert sich unter 1,4-0,0-Silylgruppenwanderung und Cyanidabspaltung zu den Acyloin - trimethylsilylethern 14 um, aus denen durch Hydrolyse die Acyloine 15 mit 80-90% Ausbeute entstehen.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791120616
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    Zweifache Deprotonierung von 2-Aryl-1-nitroethanen Umpolung der Nitroolefin-Reaktivität (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 234-248 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Double Deprotonation of 2-Aryl-1-nitroethanes.  -  Umpolung of the Nitroolefin Reactivityβ-Arylnitroethanes 4 are doubly deprotonated to the dilithio derivatives 6 when treated with two equivalents of n-butyllithium in HMPTA-containing THF at -80 to -90°C. The reagents (6) may be considered as the products (see 3 and 16b) of reduction of ω-nitrostyrenes 2, They react with haloalkanes (→ 7), aldehydes and ketones (→ 8), α,β-unsaturated ketones (→ Michael adducts 13 and 14), and ω-nitrostyrenes (→ 15) in the benzylic position. With acyl chloride and chloro-trimethylsilane attack occurs probably on an oxygen of 6 (see intermediates 17-19). A representation of the novel reagents, best compatible with the chemical results, is that of super-enamines 16b; their charge affinity is compared with that of nitroethanes (the precursors) and that of nitroethylenes (the oxidized forms, see 2 → 3), and it is shown in table 1 that they are nitroolefins with reactivity umpolung or homonitronates. The comparison made in table 2 demonstrates that the dilithio derivatives 6 are synthetically equivalent with enamines and enolates of normal reactivity (“double umpolung”).
    Notes: β-Arylnitroethane 4 können bei -80 bis -90°C in HMPTA-haltigem THF mit zwei Equivalenten n-Butyllithium zu den Dilithiumderivaten 6 doppelt deprotoniert werden, die man als Reduktionsprodukte (s. 3 und 16b) von ω-Nitrostyrolen 2 auffassen kann. Sie reagieren mit Alkylhalogeniden (→ 7), Aldehyden und Ketonen (→ 8), α,β-ungesättigten Ketonen (→ Michael-Addukte 13 und 14) und ω-Nitrostyrolen (→ 15) am benzylischen C-Atom. Säurechlorid und Trimethylchlorsilan greifen wahrscheinlich am Sauerstoff an (s. Zwischenprodukte 17-19). Als mit den chemischen Befunden am besten vereinbare Schreibweise für die neuartigen Reagentien schlagen wir die von Super-enaminen 16b vor; in Tab. 1 ist ihre Ladungsaffinität mit der von Nitroethanen (den Vorläufern) und von Nitroethylenen (den oxidierten Formen, s. 2 → 3) verglichen und gezeigt, daß sie umgepolte Nitroolefine oder Homonitronate sind. Die Gegenüberstellung in Tab. 2 demonstriert. Daß die Dilithiumverbindungen 6 als Synthesebausteine für Amine und Carbonylverbindungen normale Reaktivität haben („Doppelumpolung“).
    Additional Material: 2 Tab.
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    Unerwartete Ringschlußreaktionen 2,2-disubstituierter N-Alkoxy-3-hydroxypropionamide mit Arylisocyanaten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 600-606 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Unexpected Cyclisations of 2,2-Disubstituted N-Alkoxy-3-hydroxypropionamides with Aryl IsocyanatesTreatment of 2,2-disubstituted N-alkoxy-3-hydroxypropionamides (8) with aryl isocyanates (9) in a mole ratio of 1:2 in boiling benzene and in the presence of triethylamine yields 3-alkoxytetrahydro-2H-1,3-oxazine-2,4-diones (10) and 3-aryltetrahydro-2H-1,3-oxazine-2,4-diones (11). Formation of 10 and 11 depends largely on the nature of the substituents at C-2 of 8. In consequence of the cyclisation reactions ureas of type 13 and 14 and the 3-alkoxybiuret 15 are produced.
    Notes: 2,2-Disubstituierte N-Alkoxy-3-hydroxypropionamide (8) reagieren mit Arylisocyanat (9) im Molverhältnis 1:2 bei 80°C in Gegenwart von Triethylamin zu 3-Alkoxytetrahydro-2H-1,3-oxazin-2,4-dionen (10) und 3-Aryltetrahydro-2H-1,3-oxazin-2,4-dionen (11). Die Cyclisierungsrichtung zu 10 oder 11 wird maßgeblich von der Natur der Substituenten an C-2 von 8 bestimmt. Als Folge der Cyclisierungen lassen sich die Harnstoffe 13 und 14 sowie das 3-Alkoxybiuret 15 isolieren.
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    Nucleosidtransformationen, V. Umwandlung von Guanosin in 2′-Desoxy-, 3′-Desoxy-, 2′,3′-Anhydro- sowie xylo-Guanosin (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 625-639 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleoside Transformations, V. Transformation of Guanosine into 2′-Deoxy, 3′-Deoxy-, 2′,3′-Anhydro- and xylo-Guanosine3′-und 2′-deoxyguanosine (12 and 13, respectively) are obtained from guanosine (1) upon reaction with trimethyl orthoacetate, pivaloyl chloride/pyridine, tributyltin hydride and sodium methylate through the intermediates 2, 3a/4a. 2-N,5′-O-Dipivaloyl-2′,3′-anhydroguanosine (14) is formed on treatment of the 3′-iodoguanosine derivative 10 with potassium phthalimide. The 2′.3′-anhydroderivatives 14-16 form N-3 → C-3′-cyclonucleosides in aqueous solution. Stirring of 14 with a boron trifluoride etherate solution yields xylo-guanosine derivative 22.
    Notes: 3′-und 2′-Desoxyguanosin (12 bzw. 13) werden, ausgehend von Guanosin (1), durch Umsetzung mit Orthoessigsäure-trimethylester, Pivaloylchlorid/Pyridin, Tributylzinnhydrid und Natriummethylat über die Zwischenstufen 2, 3a/4a dargestellt. 2-N,5′-O-Dipivaloyl-2′,3′-anhydroguanosin (14) entsteht bei Behandlung des 3′-Iodguanosin-Derivats 10 mit Phthalimidkalium. In wäßriger Lösung zeigen die 2′,3′-Anhydroguanosin-Derivate 14-16 N-3 → C-3′-Cyclonucleosid-Bildung. Das xylo-Guanosin-Derivat 22 entsteht aus 14 beim Rühren mit einer Bortrifluoridetherat-Lösung.
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    Zum Mechanismus der Hydrierung bei Friedel-Crafts-Reaktionen α,β-ungesättigter Säuren mit Benzol (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 689-699 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Mechanism of Hydrogenation During Friedel-Crafts Reactions of α,β-Unsaturated Acids with BenzeneThe intermediate in the reaction of 3,3-diphenylpropenoic acid (1) with benzene/AlCl3 is the resonancestabilized carbenium ion 8. It reacts to give a mixture containing the products of hydrogenation 2 and of addition of benzene 3. Several artefacts of the working up (4 - 7) are found.  -  In the reactions of deuterated compounds hydrogen scrambling both in the phenyl groups and  -  to a smaller extent  -  in the α-position occurs.  -  Hydrogen (hydrid ions) derived from benzene, not from the side chain of a second molecule 1, is transferred to the β-position of 1.
    Notes: Die Umsetzung von 3,3-Diphenylpropensäure (1) mit Benzol/A1Cl3 führt über das mesomeriestabilisierte Carbenium-Ion 8 zu einem Substanzgemisch, in dem neben dem Hydrierungs- und dem Benzoladditionsprodukt (2 bzw. 3) Artefakte der Aufarbeitung,(4 - 7) enthalten sind.  -  Bei Einsatz deuterierter Ausgangsverbindungen tritt Äquilibrieren der Aryl- und (in geringem Umfang) der α-ständigen Wasserstoffe ein.  -  Bei der Hydrierung von 1 wird Wasserstoff des Benzols  -  nicht aber Wasserstoff aus der Seitenkette eines zweiten Moleküls 1  -  als Hydrid-Ion in die β-Stellung von 1 eingebaut.
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    Zur Autoxidation von cyclischen Iminen, I (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 734-742 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Autoxidation of Cyclic Imines, IIn a noncatalyzed reaction cyclic imines, e. g. 1a-d, bearing one or two α-tert. carbon atoms are oxidized by molecular oxygen. Usually, the products are relatively unstable α-iminohydroperoxides, which are subject to further rearrangement or reduction. These compounds are partially further oxidized. The isolation of the products as well as their structure elucidation by spectroscopic methods are established.
    Notes: Cyclische Imine mit einem oder zwei tert. α-C-Atomen, z.B. 1a-d, werden durch nichtsensibilisierten Sauerstoff oxidiert. Primär entstehen dabei meist instabile α-Iminohydroperoxide, die Folgereaktionen wie Umlagerung und Reduktion eingehen. Diese Verbindungen werden teilweise erneut oxidiert. Die Produkte der Autoxidation werden isoliert und ihre Konstitutionen ermittelt.
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    Schonende Veresterung von N-terminal geschützten Aminosäuren mittels der Vier-Komponenten-Kondensation (4 CC) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 776-777 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mild Esterification of N-protected Amino Acids via Four-Component Condensation (4 CC)We describe the esterification of N-protected amino acid derivatives, e. g. glycine derivatives and Boc-Leu-OH, with methanol or ethanol, respectively, by the action of an enamine and an isocyanide.
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    Notizen. Dimerisierung von Diphenyl(trifluoracetyl)phosphanoxid (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 773-775 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dimerization of Diphenyl(trifluoroacetyl)phosphane OxideAt -25°C the phosphane oxide CF3C[(O)P(O)Ph2]2OC(O)CF3 (1) dimerizes to the trifluoroacetate CF3C[(O) PPh2]2OC(O)CF3 (2a), which is sensitive to hydrolysis and, at 40°C is transformed irreversibly into the phosphinate CF3C[(O)PPh2][OP(O)Ph2]C(O)CF3(3a). In contrast to 2a, the thermally more stable homologous octanate C7F15C[(O)PPh2]2OC(O)C7F15 (2b) is obtained from Ph2PCI and C7F15CO2H.
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    Masthead (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/cber.19791120301
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    In memoriam Walter Hieber 1895-1976 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. XXI 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/cber.19791120241
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    Heterocyclische Siebenring-Verbindungen, XXII. Synthese und thermische Umlagerung von substituierten 4-Phenyl-1-benzothiepin-1-oxiden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 781-792 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Seven-membered Ring Compounds, XXII. Synthesis and Thermolysis of Substituted 4-Phenyl-l -benzothiepin 1-Oxides4-Phenyl-l-benzothiepin l-oxides 3a and b have been prepared as well via the benzothiepinone 1-oxide 2 as by direct oxidation of the parent 1-benzothiepins 6a and b. The synthesis of 3c and d was only accomplished by the second way. Further oxidation of 3a-d yielded the thermally stable dioxides 4a-d. Thermolysis of 3a-d produced the corresponding naphthalenes 5a-d by elimination of SO. The rates of the reaction 3→5 have been estimated for one temperature each.
    Notes: Die 4-Phenyl-l-benzothiepin-l-oxide 3a und b wurden sowohl über das Benzothiepinon-1-oxid 2 als auch durch direkte Oxidation der entsprechenden 4-Phenyl- 1-benzothiepine 6a und b dargestellt. Die Synthese von 3c und d erfolgte nur auf dem zweiten Weg. Weiteroxidation von 3a-d führte zu den thermisch stabilen Dioxiden 4a-d. Die Thermolyse von 3a-d lieferte unter Abspaltung von SO die entsprechenden Naphthaline 5a-d. Die Geschwindigkeitskonstanten der Reaktion 3→5 wurden für je eine Temperatur bestimmt.
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    Bevorzugte O-Glycosidbildung bei der Ribosidierung von 5-Methyl-2-methylthio-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-on (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 799-806 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Favoured Formation of an O-Glycoside during Ribosidation of 5-Methyl-2-methylthio-7H-pyrrolo-[2,3-d]pyrimidin-4(3H)-one6-Amino-5-(2,2-diethoxy-l-methylethyl)-2-mercaptopyrimidin-4-ol (3a) has been prepared via condensation of racem. ethyl 2-cyano-4,4-diethoxy-3-methylbutyrate (2) and thiourea. Alkylation of 3 a at 2-SH with dimethyl sulfate is accompanied by ring closure yielding 5-methyl-2-methylthio-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-one (4b). Silylation of 4b followed by reaction with 2,3,5-tri-O-acetyl-1-bromo-D-ribofuranose in the presence of mercury(II) salts (Wittenburg conditions) gives the O-glycoside 6a and not the N-7-glycoside formerly obtained during ribosidation of 2-methylthio-7H-pyrrolo[2,3-b]pyrimidin-4(3H)-one12). Hydrolysis of 6a under mild conditions leads to deacetylation giving 5-methyl-2-methylthio-4-(D-ribofuranosyloxy)-7H-pyrrolo[2,3-d]pyrimidine (6b). The latter compound shows UV spectra similar to 4-methoxy-5-methyl-2-methylthio-7H-pyrrolo[2,3-d]pyrimidine (4c) down to pH 2, but at lower pH values hydrolysis of the glycosidic bond occurs.
    Notes: 6-Amino-5-(2,2-diethoxy-1-methylethyl)-2-mercaptopyrimidin-4-of (3 a) wurde durch Kondensation von racem. 2-Cyan-4,4-diethoxy-3-methylbuttersäure-ethylester (2) und Thioharnstoff gewonnen. Die Alkylierung von 3a mit Dimethylsulfat führt zur Methylierung an 2-SH, wobei gleichzeitig Cyclisierung zu 5-Methyl-2-methylthio-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-on (4b) erfolgt. Verknüpft man silyliertes 4 b mit 2,3,5-Tri-O-acetyl-l-brom-D-ribofuranose in Gegenwart von Quecksilber(II)-Salzen (Wittenburg-Bedingungen), so entsteht das O-Glycosid 6a und nicht wie bei der Reaktion von 2-Methylthio-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-on das N-7-Glycosid12). Durch milde Hydrolyse von 6a erhält man 5-Methyl-2-methylthio-4-(D-ribofuranosyloxy)-7H-pyrrolo[2,3-d]pyrimidin (6b), dessen UV-Spektren bis pH 2 denen von 4-Methoxy-5-methyl-2-methylthio-7H-pyrrolo[2,3-d]pyrimidin (4c) gleichen, im stärker Sauren jedoch Glycosid-Hydrolyse anzeigen.
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    Totalsynthese von Papaverrubin E (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 849-852 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Total Synthesis of Papaverrubine EThe phthalide isoquinoline alkaloid (-)-bicuculline (la), which has previously been prepared by total synthesis, is transformed into racemic papaverrubine E (±)-(6a), its natural (+)- and its unnatural (-)-enantiomer.
    Notes: Das totalsynthetisch zugängliche Phthalidisochinolinalkaloid (-)-Bicucullin (la) wird in das Racemat des Benzazepinalkaloids Papaverrubin E (±)-(6a) sowie in sein natürliches (+)-bzw. unnatürliches (-)-Enantiomeres übergeführt.
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    Basische Metalle, XI. Kationische (Cyclopentadienyl)rhodium-Komplexe mit Rh—H-, Rh—C-, Rh—Ge-, Rh—Sn- und Rh—Halogen-Bindungen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 834-843 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Metals, XI. Cationic (Cyclopentadienyl)rhodium Complexes Containing Rh—H-, Rh—C-, Rh—Ge-, Rh—Sn-, and Rh—Halogen Bonds[C8H12RhCl]2 reacts with excess trimethylphosphane to give [(PMe3)4Rh]Cl (1). A very rapid exchange of the phosphane ligands occurs in solution of 1. The reaction of 1 with T1C5H5 leads to the complex C5H5Rh(PMe3)2 (9), in which the metal atom is a strong Lewis base. 9 reacts very readily with electrophiles Y+ to give the cations [C5H5(PMe3)2RhY]+ which possess stable Rh—H, Rh-alkyl, Rh—acyl, Rh—Ge, Rh—Sn, and Rh—halogen bonds. They were isolated as PF6 salts [Y = H (2), CH3 (3), C2H5 (4), COCH3 (10), COC6H5 (11), COC6H4OMe-(p) (12), GeMe3 (7). SnMe3 (8). Br (15), cl (13), I (14). The cation Me3SiC5H4(PMe3)2RhH ]+ is formed together with [C5H5(PMe3)2RhH]+ in the reaction of 9 with CF3SO3SiMe3, in ether. Reduction with NaH in THF gives Me3SiC5H4Rh(PMe3)2.
    Notes: [C8H12RhCl]2 reagiert mit einem Überschuß von Trimethylphosphan zu [(PMe3)4Rh]Cl (1). In Lösungen von 1 findet ein sehr rascher Austausch der Phosphanliganden statt. Die Reaktion von 1 mit TIC5H5 führt zu dem Komplex C5H5Rh(PMe3)2 (9), der ein stark Lewis-basisches Metallatom besitzt. 9 reagiert mit Elektrophilen Y+ sehr bereitwillig zu den Kationen [C5H5(PMe3)2RhY]+ die stabile Rh—H-, Rh—Alkyl-, Rh—Acyl-, Rh—Ge-, Rh—Sn- und Rh—Halogen-Bindungen besitzen und als PF6-Salze isoliert werden [Y = H (2), CH3 (3), C2H5 (4), COCH3 (10), COC6H5 (11), COC6H4OMe-(p) (12), GeMe3 (7), SnMe3 (8), Br (15), Cl (13). 1(14)]. Bei der Reaktion von 9 mit CF3SO3SiMe3 in Ether entsteht neben [C5H5(PMe3),2RhH] + das Kation [Me3SiC5H4(PMe3)2RhH]+. Die Reduktion mit NaH in Tetrahydrofuran ergibt Me3SiC5H4Rh(PMe3)2.
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    Photoelektronenspektren und Konformationen bi- und tricyclischer Hexahydro-1,2,4,5-tetrazine (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 853-861 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Conformations of Bi- and Tricyclic Hexahydro-1,2,4,5-tetrazinesThe photoelectron spectra of three tricyclic (2-4) and three bicyclic (5-7) hexahydro-1,2,4,5-tetrazines have been interpreted with regard to gas phase conformations. The interactions of the n-orbitals have been studied by MINDO/2 calculations for different conformations of hexahydro-1.2.4,5-tetrazine (1). The observed n-electron ionization potentials permit the identification of tetraequatorial forms of 2-4 and diequatorial-diaxial forms of 5-7 as the dominant conformers. In addition, for 2 and 5 other less stable conformers could be detected.
    Notes: Die Photoelektronenspektren von drei tricyclischen (2-4) und von drei bicyclischen (5-7) Hexahydro-1,2,4,5-tetrazinen wurden hinsichtlich der in der Gasphase vorliegenden Konformeren ausgewertet. Für die infrage kommenden Konformationen wurden zum Studium der Wechselwirkung der n-Orbitale MINDO/2-Rechnungen an der Stammverbindung (1) ausgeführt. Anhand der beobachteten n-Ionisationsbanden lassen sich bei 2-4 tetraäquatoriale und bei 5-7 diäquatorial-diaxiale Formen als stabilste Konformere identifizieren. Bei 2 und 5 wurden daneben weniger stabile Konformere nachgewiesen.
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    Struktur und innere Beweglichkeit sterisch fixierter s-cis-Butadiene (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 890-898 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure and Internal Flexibility of Sterically Fixed s-cis-ButadienesForce Field Calculations yield a coplanar arrangement of the π systems of the vicinal exo-methylene derivatives 1 and 2 of cyclobutane and cyclopentane and of the corresponding derivatives 4-7 of norbornane, bicyclooctane, bicyclononane and bicyclooctene. The detailed geometry of the cis-butadiene unit is essentially determined by the ring system. For the cyclohexane derivative 3 on the other hand a chair conformation is obtained. 2,5 and 6 are rather flexible molecules for which torsions of the π system up to 20° require energies less than 5 kJ/mol, whereas for the more rigid systems 1, 4 and 7 approximately 10 kJ/mol are necessary for twisting the π system by 10°.
    Notes: Kraftfeldrechnungen ergeben für die vicinalen exo-Methylenderivate 1 und 2 des Cyclobutans und des Cyclopentans sowie für die entsprechenden Derivate 4-7 des Norbornans, Bicyclooctans, Bicyclononans und des Bicyclooctens eine planare Anordnung des π-Systems. Dessen genaue Geometrie im wesentlichen durch das cyclische Gerüst bestimmt wird. Das Cyclohexanderivat 3 dagegen liegt in einer Sesselform vor. Die Moleküle 2, 5 und 6 zeichnen sich durch große Flexibilität aus, Torsionen des π-Systems bis etwa 20° erfordern Energien von weniger als 5 kJ/mol, während für die starreren Systeme 1,4 und 7 bereits bei Verdrillungen um 10° etwa 10 kJ/mol erforderlich sind.
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    Ligandstruktur und Komplexierung, XLIV. Synthese und Selektivität neuartiger vierarmiger nichtcyclischer Neutralliganden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 899-907 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Structure and Complexation, XLIV. Synthesis and Selectivity of New Four-Armed Noncyclic Neutral LigandsNew, noncyclic neutral ligand systems 4-6 and 8-11 of the tetrapode type 3, equipped with various end groups, were synthesized. The cation selectivity depends on the structure of the end groups. The potentiometrically determined values of the complex stability constants as a rule lie between those of the analogous tripode (2) and dipode ligands (1). Numerous complexes between the four-armed complexing agents and several dipodands (14-16) and alkali and alkaline earth metal salts are reported.
    Notes: Neue nichtcyclische Neutralligandsysteme 4-6 und 8-11 vom Tetrapodentyp 3 mit verschiedenen Endgruppen wurden synthetisiert. Die Kation-Selektivität hängt von der Endgruppenstruktur ab. Die potentiometrisch bestimmten Komplexstabilitätskonstanten liegen i. a. zwischen denjenigen der Tripoden- (2) und Dipoden-Liganden (1). Zahlreiche kristalline Komplexe der vierarmigen Komplexbildner sowie einiger zum Vergleich synthetisierter neuer Dipodanden (14-16) mit Alkali- und Erdalkalimetallsalzen wurden erhalten.
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    Über N-Silyl- und N-Germylpyridinyl-Radikale sowie ihre Stabilisierungsreaktionen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 936-949 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-Silyl and N-Germylpyridinyl Radicals, and Their Stabilization ReactionsPyridines, functionally substituted in 2-, 3-, or 4-position, give N-silylpyridinyls (3, 7, 11, 16, 19, 23) upon reaction with (Me3Si)2Hg, and further on mostly N,ω-bis(silyl) derivatives (5), tetrahydro-4,4′-or -2,2′-bipyridines (9, 17, 20, 21, 24, 25), depending on mesomeric and steric conditions. 2- and 3-acylpyridines yield O-silylated hydropyridoins (27, 30), 2-cyanopyridine forms a persistent pyridinyl (29). N-Germylpyridinyls (32-34) are generated for the first time. With (Me3Ge)2Hg, they are formed, however, only in the case of substituted pyridines of low electron density or strong mesomeric stabilization of the radicals. Several N ω-bis(germyl)-dihydropyridines (36, 37) rearrange, in part even at -30°C, with a surprising N, C-migration of a germyl residue, restoring the aromatic system, giving 35, 39. ESR data are given for most of the generated radicals.
    Notes: In 2-, 3- oder 4-Stellung funktionell substituierte Pyridine geben mit (Me3Si)2Hg N-Silylpyridinyle (3, 7, 11, 16, 19, 23), die je nach Mesomeriestabilisierung und sterischer Hinderung meistens zu N,ω-Bis(silyl)-Derivaten (5) oder zu Tetrahydro-4,4′- bzw. -2,2′-bipyridinen (9, 17, 20, 21, 24, 25) weiterreagieren. 2- und 3-Acylpyridine ergeben O-silylierte Hydropyridoine (27, 30), 2-Cyanpyridin ein kinetisch stabiles Pyridinyl (29). N-Germylpyridinyle (32-34) werden erstmals erhalten. Sie entstehen mit (Me3Ge)2Hg nur im Falle elektronenarmer substituierter Pyridine bzw. starker Mesomeriestabilisierung der Radikale. Bei N,ω-Bis(germyl)dihydropyridinen (36, 37) wurde, z. T. schon bei -30°C, eine überraschende N,C-Wanderung eines Germylrestes unter Rückbildung des aromatischen Systems zu 35, 39 gefunden. Für die meisten der erhaltenen Radikale werden die ESR-Daten angegeben.
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    Stoffwechselprodukte von Mikroorganismen, 172. Isolierung des Antibioticums semi-Vioxanthin aus Penicillium citreo-viride und Synthese des Xanthomegnins (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 957-978 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metabolic Products of Microorganism, 172. Isolation of the Antibiotic semi-Vioxanthin from Penicillium citreo-viride and Synthesis of XanthomegninBesides xanthomegnin (16 b), 3,4-dehydroxanthomegnin (29a), viomellein (23) and vioxanthin (3) from Penicillium citreo-viride under different culture conditions semi-vioxanthin (7) was isolated. Structure 7 has been established by its spectra and the fact that oxidation with Fremy's salt gives 3,4,6,9-tetrahydro-10-hydroxy-7-methoxy-3-methyl-1,6,9-trioxo-1H-naphtho[2,3-c]pyran (9a = semi-xanthomegnin). -9c, prepared by demethylation of 9a, was dimerized by potassium peroxydisulfate/sodium hydroxide and methylated, giving 16b. Synthetic 16b and authentic xanthomegnin were identical, which verifies the structure revised by Höfle and Röser9) and shows, that the dyes of the xanthomegnin series are biogenetically homogenous. - The metabolic products of the strain inhibit the growth of bacteria. 16b and 26 furthermore have an effect against insects.
    Notes: Neben Xanthomegnin (16b), 3,4-Dehydroxanthomegnin (29 a), Viomellein (23) und Vioxanthin (3) wurde aus Penicillium citreo-viride unter veränderten Kulturbedingungen semi-Vioxanthin (7) isoliert. Konstitution 7 folgt aus den Spektren und dem Befund, daß mit Fremy-Salz 3,4,6,9-Tetrahydro-10-hydroxy-7-methoxy-3-methyl-1,6,9-trioxo-1H-naphtho[2.3-c]pyran (9a = semi-Xanthomegnin) entsteht. - Das durch Entmethylierung von 9a zugängliche 9c ließ sich mit Kaliumpersulfat/Natriumhydroxid zu 16a dimerisieren, das zu 16b methyliert wurde. Synthetisches 16b war mit nativem Xanthomegnin identisch, was die von Höfle und Röser9) revidierte Konstitution bestätigt und beweist, daß die Farbstoffe der Xanthomegnin-Reihe biogenetisch einheitlich sind. - Die Stoffwechselprodukte des Stammes hemmen das Wachstum von Bakterien, 16b und 23 wirken ferner gegen Insekten.
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    Mikrobiologische Umwandlung von Steroiden, XVI. Synthese von 11β, 21-Dihydroxy-6, 16α-dimethyl-1,4,6,-pregnatrien-3,20-dion und dessen 11-Ketoverbindung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 979-989 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbial Transformations of Steroids XVI. Synthesis of 11β,21-Dihydroxy-6, 16α-dimethyl-1,4,6-pregnatriene-3,20-dione and of its 11-Keto Compound21-Acetoxy-5α,6α-epoxy-3β-hydroxy-6β16α-dimethyl-20-pregnanone (3a), prepared from 3β-hydroxy-6, 16α-dimethyl-5-pregnen-20-one (1) by epoxidation and chemical introduction of the 21-acetoxy group, was oxidized to 6α,21-dihydroxy-6β,16α-dimethyl-4-pregnene-3,20-dione (4) by Flavobacterium dehydrogenans and dehydrated to the 3-keto-4,6-diene 5. The 11β-hydroxy group was introduced by Curvularia lunata to give 6, and the 11α-hydroxy group by Aspergillus ochraceus to yield 8. Both compounds were dehydrogenated with Bacillus lentus to from 7 and 9. The 11α-hydroxy compound 9 was selectively acetylated to 10, which was oxidize to 11. This on saponification yielded 12.
    Notes: 21-Acetoxy-5α,6α-epoxy-3β-hydroxy-6β,16α-dimethyl-20-pregnanon (3a), dargestellt aus 3β-Hydroxy-6, 16α-dimethyl-5-pregnen-20-on (1) durch Epoxidierung und 21-Acetoxylierung, wurde mit Flavobacterium dehydrogenans zu 6α,21-Dihydroxy-6β, 16α, -dimethyl-4-pregnen-3,20-dion (4) oxidiert und zu 21-Hydroxy-6, 16α-dimethyl-4,6-pregnadien-3,20-dion (5) dehydratisiert. Mit Curvularia lunata wurde die 11β-Hydroxygruppe eingeführt zu 6, während Aspergillus ochraceus die entsprechende 11α-Hydroxyverbindung 8 ergab. Beide Verbindungen wurden mit Bacillus lentus zu 7 bzw. 9 dehydriert. Die 11α-Hydroxyverbindung 9 wurde nach selektiver Acetylierung der 21-Hydroxygruppe zu 10 zum 11-Keton 11 oxidiert, dessen Verseifung 12 ergab.
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    Neue Synthesen mit Diazodiketonen, IV. Cyclische S-Oxide (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1012-1022 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Syntheses with diazodiketones, VI. Cyclic S-OxidesThe S-oxides 4 of 3,4-dihydro-1,2,3-oxathiazines and 5 of 1,2-oxazetidines are prepared a) by thermolyzing diazodiketones 1 with N-Sulfinylamines 3; b) by condensing the 2-acylacetamides 6 which are readily accessible from 1, with thionyl chloride in the presence of a basic catalyst. From 6, the aminoacrylamides 7 are obtained. These react with thionyl chloride according to the base employed, to afford either the monocyclic 3,6-dihydro-1,2,6-thiadiazine-S-osides 10 or the 4-amino-quinolines 8, presumably via the intermediacy of an imine 9. - The introduction of the SO group into (hetero)cyclic iminocarboxamides, diamines or aminophenols give rise to the S-oxides 13 of condensed thiadieazines, 15a-c of benzothiadiazole, or 15d of benzoxathiazole, respectively.
    Notes: Die 3,4-Dihydro-1,2,3-oxathiazin- 4 und 1,2-Oxazetidin-S-oxide 5 werden a) durch Thermolyse der Diazodiketone 1 mit N-Sulfinylaminen 3 b) durch basenkatalysierte Kondensation der aus 1 leicht zugänglichen 2-Acylacetamide 6 mit Thionylchlorid hergestellt. Aus 6 weden die Aminoacrylamide 7 erhalten. Diese reagieren mit Thionylchlorid je nach der verwendeten Base entweder zu monocyclischen 3,6-Dihydro-1,2,6-thiadiazin-S-oxiden 10 oder über eine Imidoylketenimin Zwischenstufe 9 zu den 4-Aminochinolinen 8. - Der SO-Einbau mittels Thionylchlorid in (hetero)-cyclische Iminocarboxamide, Diamine und Aminophenole führt zu den S-oxiden 13 kondensierter Thiadiazine, 15a-c des Benzothiadiazols bzw. 15d des Benzoxathiazols.
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    Untersuchungen zur Modifizierung der Mannobiose und Synthese von Methyl-4-O-β-D-rhamnosyl-α-D-olivosid (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1035-1045 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on the Modification of Mannobiose and Synthesis of Methyl 4-O-β-D-Rhamnosyl-α-D-OlivosideBy acid-catalyzed reaction of α-mannobiose octaacetate (2) with trichloroethanol or phenol the glycosides 6 or 9a, and with hydrogen bromide/acetic acid the glycosyl bromide 3 are obtained. Koenigs-Knorr reaction of 3 with methanol of benzyl alcohol yields the orthester derivatives 7a or 7b, respectively. Mannobial hexaacetate 8 is obtained from 3 an d transformed into 12a by iodomethoxylation. The selective tosylations of 9b or 12b in the 6- and 6′ -positions yields the ditosylates 10 or 13a, which in turn give the corresponding diiodo compounds 11a or 5a, respectively. By subsequent reduction using nickel chloride/sodium borohydride the syntheses of the glycosides 14 and 17b of 4-O-(β-D-rhamnopyranosyl)-α-D-rhamnopyranose or 4-O-(β-D-rhamnopyranosyl)-α-D-olivopyranose, respectively, are achieved. All new compounds are characterized by peracetates, and their structural assignment is confirmed from their NMR spectra.
    Notes: α-Mannobiose-octaacetat (2) läßt sich sauer katalysiert mit Trichlorethanol oder Phenol zu den Glycosiden 6 bzw. 9a oder mit Bromwasserstoff in Eisessig zum Glycosylbromid 3 umsetzen. Koenigs- Knorr-Reaktion von 3 mit Methanol oder Benzylalkohol ergibt die Orthoester 7a bzw. 7b. Aus 3 wird Mannobial-hexaacetat 8 gewonnen und zu 12a iodmethoxyliert. 9b bzw. 12b lassen sich selektiv in 6- und 6′- Position zu 10 bzw. 13a tosylieren und anschließend in die entsprechenden Iodide 11a bzw. 15a überführen. Deren Reduktion mit Nickelchlorid/Natriumboranat in Ethanol erlaubt die Darstellung der Glycoside 14 and 17b von 4-O-(β-D- Rhamnopyranosyl)-α-D-rhamno-pyranose bzw. 4-O-0(β-D-Rhamnopysanosyl)-α-D-olivopyranose. Alle Syntheseprodukte werden durch Peracetate charakterisiert und strukturell an Hand der NMR-Spektren zugeordnet.
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    Synthese, Strukturaufklärung und Konformationsuntersuchungen 1→4-verknüpfter Disaccharidglycoside vom 2,3-Anhydro-4-O-(hex-2-enopyranosyl)-α-D-allopyranosid-Typ (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1023-1034 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Structure Elucidation, and Conformational Studies of 1→4-Linked Disaccharide Glycosides of the 2,3-Anhydro-4-O-(hex-2-enopyranosyl)-α-D-allopyranoside TypeTriacetyl-D-glucal (1) or tetraacetyl-2-hydroxy-D-glucal (6) and 2,3-anhydro-α-D-allopyranosides 2 or 7, respectively, undergo smooth acid-catalyzed allylic rearrangement reactions to yield the crystalline α-linked disaccharide derivatives 4, 5, and 9 with hex-2-enopyranosyl structure in the non-reducing rings in good yields. By hydrogenation of 4 and 5, 8 is obtained, in which the α-linkage can be demonstrated. X-ray analysis confirms the interglycoside α-linkage in the considerably stretched disaccharide derivative 5. Both the saccharide ring adopt SO5 sofa conformations, in which only C-5 and C-5′ ae observed significantly below the plane of the remaining ring atoms. The NMR data of 5 and 9 suggest also SO5 sofa conformation in solution. On the contrary the β-isomer 10 adopts 5SO sofa conformation which is consistent with the allylic effect.
    Notes: Durch sauer katalysierte Addition der 2,3-Anhydro-α-D-allopyranoside 2 bzw. 7 an Triacetyl-D-glucal (1) bzw. Tetraacetyl-2-hydroxy-D-glucal (6) lassen sich unter Allylumlagerung die α1→4-verknüpften Disaccharide 4, 5 und 9 mit Hex-2-enopyranosyl-Struktur im nicht-reduzierenden Saccharidring milde und in guten Ausbeuten kristallin gewinnen. Durch Hydrierung von 4 und 5 wird 8 erhalten, bei dem die interglycosidische α-Verknüpfung nachgewiesen wird. Die Röntgenstrukturanalyse von 5 bestätigt die α-Verknüpfung in dem erheblich gestreckten Disaccharidderivat. Beide Saccharidringe weisen eine SO5-Sofakonformation auf, bei der nur die Atome C-5 und C-5′ wesentlich aus der Ebene der übrigen Ringatome nach unten herausstehen. Konformationsbetrachtungen legen auch in Lösung für 5 und 9 das Vorliegen einer SO5-Sofakonformation nahe. Das interglycosidische β-Isomere 10 weist dagegen eine 5SO-Sofakonformation auf, was auf den Allyleffekt zurückgeführt werden kann.
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    Untersuchungen zur Modifizierung der Laminaribiose und Synthese von Methyl-3-O-β-D-chinovosyl-α-D-olivosid (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1046-1056 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on the Modification of Laminaribiose and Synthesis of Methyl 3-O-β-D-Quinovosyl-α-D-olivosideLaminaribiose (2) and the peracetates 3a and b are obtained by acetolysis of laminaran or pachyman, respectively. Via formation of the bromide 5, the β-methyl (6) and β-benzyl glycosides (7a and b) as well as the glycals 9a and b are obtained in crystalline form. Iodoalkoxylations with benzyl alcohol yield the epimeric benzyl glycosides 10a and b, whereas with methanol 11a is obtained exclusively. 11b is transformed into the dibenzylidene compounds 12a-c. the reaction of which with N-bromosuccinimide leads to the formation of the 2,6,6′- trihalo derivatives 13a and b. By subsequent reduction the title compound 14b is obtained and characterized as its peracetate.
    Notes: Ausgehend von Laminaribiose (2) und ihren Peracetaten 3a und b, die durch Acetolyse von Laminaran bzw. Pachyman zugänglich sind, lassen sich über das Bromid 5 die β-Methyl- (6) und β-Benzylglycoside (7a und b) sowie die Glycale 9a und b kristallin gewinnen. Iodalkoxylierung mit Benzylalkohol gibt die epimeren Benzylglycoside 10a und b, während mit Methanol einheitlich 11a isoliert wird. Aus 11b werden die Dibenzylidenverbindungen 12a-c dargestellt, deren Öffnung mit N-Bromsuccinimid zu den 2,6,6′-Trihalogenderivaten 13a und b führt. Durch Reduktion wird daraus die Titelverbindung 14b gewonnen und als Peracetat charakterisiert.
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    Tertiäres Phosphan/Hexachlorethan als Kondensationsreagenz für die Peptidsynthese (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1057-1063 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tertiary Phosphane/Hexachloroethane as Condensing Agent in Peptide SynthesisThe action of tertiary phosphane/hexachloroethane on N-protected amino acids and amino acid esters is found applicable for peptide synthesis. No difficulties are found when the side chains of serine, threonine, tyrosine, asparagine and glutamine are present. By addition of 1-hydroxybenzotriazole racemisation is prohibited as indicated by the test of Anderson.
    Notes: Mit dem Dehydratisierungsreagenz tertiäres Phosphan/Hexachlorethan lassen sich N-geschützte Aminosäuren und Aminosäureester in hohen Ausbeuten zu Peptiden kondensieren. Funktionelle Gruppen in den Seitenketten von Serin, Threonin, Tyrosin, Asparagin und Glutamin werden nicht angegriffen Unter Zusatz von 1-Hydroxybenzotriazol verläuft der Anderson-Test racemisierungsfrei.
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    Synthetische Arbeiten in der Reihe der aromatischen Erythrina-Alkaloide, XXIII. 1,7-Cyclo-cis-erythrinane (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1110-1125 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Aromatic Erythrina Alkaloids, XXIII. 1,7-Cyclo-cis-erythrinanesThe 1,7-cyclo-cis-erythrinane derivative 17 is formed by heating the bromo compound 13 with potassium hydroxide in diethylene glycol to 180°C. Hydrolysis of 17 yields the ketone 18 which, by reactions of the carbonyl group, is transformed into the cyclic compounds 19 - 21 and 27 - 33. The cyclopropane ring is easily cleaved by reduction to give the unsaturated lactam 10 or the saturated lactam 1. The 1,7-cyclo-cis-erythrinane structures 37 and 38 can be synthesized by way of the cyclic olefin 35.
    Notes: Durch Erhitzen der Bromverbindung 13 mit Kaliumhydroxid in Diethylenglycol auf 180°C entsteht das 1,7-Cyclo-cis-erythrinan-Derivat 17. Nach Hydrolyse zum Keton 18 erhält man durch Umwandlung der Ketogruppe die Cycloverbindungen 19 - 21 und 27 - 33. Reduzierende Bedingungen spalten den Cyclopropanring sehr leicht auf unter Bildung des Olefinlactams 10 oder des gesättigten Lactams 1. Über das Cycloolefin 35 gelingt die Darstellung von 37 und der zugehörigen Base 38 mit dem Grundgerüst der 1,7-Cyclo-cis-erythrinane.
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    Synthetische Arbeiten in der Reihe der aromatischen Erythrina Alkaloide, XXIV. Über die Bromierungsprodukte von 15,16-Dimethoxy-cis-erythrinan-2,8-dion (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1126-1139 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Aromatic Erythrina Alkaloids, XXIV. On the Products of Bromination of 15,16-Dimethoxy-cis-erythrinane-2,8-dioneBromination of 1 as well as hydrolysis of 5 (with inversion at C-l) yields the bromoketolactam 2. This can be converted back to 5, again with inversion. On reduction of 2 with sodium tetrahydridoborate, the bromohydrines 11-13 and the epoxide 17 are obtained. The epimeric bromoketolactam 6 cannot be isolated, but is an intermediate in the formation of 12 and 13. 2 reacts with potassium hydroxide in methanol or ethylene glycol to give the hydroxyacetals 18 and 19, respectively. From 1 the dibromoketones 24 and 25 were prepared which exhibit unusual spectral properties.
    Notes: Das Bromketolactam 2 wird aus 1 durch Bromierung oder aus 5 durch Hydrolyse unter Umkehrung der Konfiguration an C-l erhalten. Auch die entgegengesetzte Reaktion von 2 nach 5 verläuft unter Umkehr. Mit Natriumboranat liefert 2 die Bromhydrine 11, 12, 13 und das Epoxid 17. Bei der Bildung von 12 und 13 ist wieder das selbst nicht faßbare epimere Bromketolactam 6 Zwischenprodukt. Die Umsetzung von 2 mit Kaliumhydroxid in Methanol oder Ethylenglycol führt zu den Hydroxyacetalen 18 oder 19. Die aus 1 dargestellten Dibromketone 24 und 25 haben auffallende spektroskopische Eigenschaften.
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    Methylschwefelpentafluorid und einige seiner Derivate (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1140-1146 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methylsulfurpentafluoride and Some of its DerivativesMethylsulfurpentafluoride (5) was systematically synthesized, starting with SF5Cl and ketene. It is stable at room temperature against HF elimination. The reaction of SF5Cl and diketene gives compounds of the type SF5—CH2—X, but the title compound is not produced in this way.
    Notes: Methylschwefelpentafluorid (5) wurde systematisch synthetisiert, ausgehend von SF5Cl und Keten. Es ist bei Raumtemperatur stabil gegen HF-Eliminierung. Die Reaktion von SF5Cl und Diketen führt zu einer Vielzahl anderer Verbindungen des Typs SF5—CH2—X, in einfacher Weise jedoch nicht zur Titelverbindung.
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    Synthesen biologisch wichtiger Kohlenhydrate, 20. N-Acetyl-1,4-di-O-acetyl-β-DL-vancosamin (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3273-3281 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Biologically Important Carbohydrates, 20. N-Acetyl-1,4-di-O-acetyl-β-DL-vancosamineClaisen rearrangement of 1-methyl-2-butenyl vinyl ether (3) yields trans-3-methyl-4-hexenal (4), the ethylene acetal 5 of which is aminated with selenium and chloramine T forming a mixture of the 3-methyl-3-tosylamino- (6) and 3-methyl-6-tosylamino derivatives 7. After detosylation of 6 and N-acetylation trans-3-acetylamino-3-methyl-4-hexenal ethylene acetal (9) is cis-hydroxylated to give 10/11. Cleavage of the protecting group at C-1 and peracetylation gives n-acetyl-1,4-di-O-acetyl-β-DL -vancosamine (13). The constitution of 13 is proved by mass spectrometry and the lyxo-configuration is assigned with high probability on the basis of 1 H NMR investigation *).
    Notes: Die Claisen-Umlagerung von (1-methyl-2-butenyl)-vinyl-ether (3)liefert trans-3-Methyl-4-hexenal(4), dessen Ethylenacetal 5 mit Selen und Chloramin-T zu den 3-Methyl-3-tosylamino-(6) und 3-Methl-6-tosylamino-Derivaten 7 aminiert wird. Nach Detosylierung von 6 und N-Acetylierung wird trans-3-Acetylamino-3-methyl-4-hexenal-ethylenacetal (9) zu 10/11 cis-hydroxyliert. Abspaltung der Schutzgruppe an C-1 und Peracetylierung liefert n-Acetyl-1,4-di-O-acetyl-β-DL-vancosamin (13), dessen Konstitution durch MS bewiesen und dessen lyxo-Konfiguration durch 1 H-NMR-Untersuchungen weitgehend gesichert wird *).
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    Monomere Bis[dialkylphosphonium-bis(methylid)]-Komplexe des Nickels, Palladiums und Platins (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3311-3317 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Monomeric Bis[dialkylphosphonium bis(methylide)] Complexes of Nickel, Palladium, and PlatinumThe reaction of bis(trimethylphosphane) complexes of NiCl2 and PdCl2 with the bulky ylide CH3[(CH3)3C]2P = CH2 in a molar ratio 1:4 leads to transylidation and formation of corresponding phosphonium salt and the new ylide chelates [(CH3)3C]2P(CH2)2M(CH2)2P[(CH3)3]2; M = Ni (1); M = Pd (2). In similar experiments with PtCl2, only the salt-like half-complex [(CH3)3C]2P(CH2)2Pt[P(CH3)3]2+Cl¯ (3) is obtained. However, the reaction of the lithiated ylide with (l,5-cyclooctadiene)PtCl2 yields the missing Pt analogue of the above type (4). Contrary to the results with Pd11, Ni11 reacts with 1 -methyl- l-methylene-λ.5-phospholane and -phosphorinane to give monomeric bis-chelates of the formula CH2]nP(CH2):Ni(CH2)2:P[CH2]n; n = 4 (5): n = 5 (6). The monomeric Structure was confirmed by 1H, 13C, 31P NMR, and mass spectra, and attributed to steric effects in the case of the tert-butyl compounds. The opening of the CPC chelate angle induced by the strained ring system of the cyclic ylides appears to favour pseudo-allyl type interactions with the nickel centre.
    Notes: Die Bis(trimethylphosphan)-Komplexe von NiCl2 und PdCl2 reagieren mit dem sterisch anspruchsvollen Ylid CH3[(CH3)3C]2P≡CH2 im Molverhältnis 1:4 unter Umylidierung zum zugehörigen Phosphoniumsalz und den neuen Ylid-Chelaten [(CH3)3C]2P(CH2)2M(CH2) P[2CH3)3 M] ≡Ni (1), M = Pd (2). Mit PtCl2 entsteht dagegen bei deràrtigen Ansätzen nur der salzartige Halbkomplex [(CH3)3C]2P(CH2)2Pt[P(CH3)3]2-;Cl+ (3). Die Reaktion des lithiierten Ylids mit (l,5-Cyclooctadien)PtCI2 liefert dagegen das fehlende Pt-Analoge des obigen Typs (4). - lm Gegensatz zu den Verhältnissen bei Pd11 ergibt NiII auch mit l-Methyl-l-methylen-λ5-phospholan und -phosphorinan monomere Doppelchelate der Formel [CH2]nP(CH2)2Ni(CH2)2P[CH2]n: n = 4(5), n = 5 (6). Die Monomerstruktur wurde durch 1H. 13C, 31P-NMR- und Massenspektren gesichert und bei den tert-Butyl-Verbindungen durch sterische Effekte gedeutet. Bei den cyclischen Yliden begünstigt die starke Winkelöffnung der Chelateinheit eine Pseudo-Allylwechselwirkung mit dem Nickelzentralatom.
    Additional Material: 3 Ill.
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    Reaktivität von Metall-Metall-Bindungen. Wiederholte Schließung und Öffnung einer Fe - Co-Bindung durch Eliminierung und Addition (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3390-3412 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactivity of Metal-Metal Bonds. Repeated Formation and Cleavage of a Fe - Co Bond by Elimination and AdditionIn arsenic-bridged dinuclear metal carbonyl complexes the sequence of formation and cleavage of the metal-metal bond by elimination of CO and addition of a phosphine ligand is repeatable. Starting from (CO)4Fe -AsMe2 - Co(CO)4 it can be performed four times in a row. The ligand which in each case is introduced at the cobalt atom can be transferred to the iron atom by isomerisation in complexes with and without metal-metal bonds. With Pme3 and P(OMe)3 as phosphines and up to the introduction of three ligands thus 44 different complexes are possible of which 35 were isolated (scheme 1). By side reactions or for the purpose of comparisons further complexes with chain-like arrangements of metal and P or As atoms were obtained. When four ligands are introduced the elimination/addition scheme reaches a natural limit since then phosphine elimination is preferred to CO elimination. The described sequences can be understood as basic patterns of catalytic activity by opening of metal-metal bonds.
    Notes: In arsenverbrückten Metallcarbonyl-Zweikernkomplexen ist die Sequenz von Bildung und Lösung der Metall-Metall-Bindung durch Eliminierung von CO und Addition eines Phosphanliganden wiederholbar. Ausgehend von (CO)4Fe-AsMe2-Co(CO)4 läßt sie sich viermal hintereinander durchführen. Der jeweils am Cobaltatom eingeführte Ligand kann in Komplexen mit und ohne Metall-Metall-Bindung durch Isomerisierung auch auf das Eisenatom übertragen werden. Mit PME3 und P(OMe)3 als Phosphanen sind so bis zur Einführung von drei Liganden 44 verschiedene Komplexe denkbar, von denen 35 isoliert wurden (Schema 1). Durch Nebenreaktionen bzw. zu Vergleichszwecken wurden weitere Komplexe mit kettenförmiger Anordnung von Metall- und P- bzw. As-Atomen erhalten. Nach der Einführung von vier Liganden findet das Eliminierungs/ Additions-Schema eine natürliche Grenze, da dann Phosphan-Eliminierung gegenüber der CO-Eliminierung bevorzugt wird. Die beschriebenen Sequenzen lassen sich als Grundmuster katalytischer Aktivität durch Öffnung von Metall-Metall-Bindungen verstehen.
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    Darstellung und Eigenschaften von Carbamoyleisen-Komplexen; Kristallstruktur von Nickelbis[tetracarbonyl-μ-(dimethyl-carbamoyl-O)-eisen] (2 Ni-Fe) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3413-3423 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of Carbamoyliron Complexes;. Crystal Structure of Nickelbis[tetracarbonyi-μ-(dimethylcarbamoyl-O)-iron](2M-Fe)The carbamoyl complex 1 can be transaminated with piperidine and pyrrolidine to give 2 and 3. 1-3 react with anhydrous nickel bromide to yield the nickelbis[tetracarbonyl-μ-(carbamoyl-O)-iron] (2 Ni-Fe) complexes 4-6, which are studied by spectroscopic methods. The X-ray analysis proves a linear iron nickel iron spine in 4. The crystals are triclinic, space group PT, with one molecule in the unit cell.
    Notes: Der Carbamoylkomplex 1 läßt sich mit Pyrrolidin und Piperidin zu 2 und 3 umaminieren. 1-3 reagieren mit wasserfreiem Nickelbromid zu den Nickelbis[tetracarbonyl-μ-(carbamoyl-0)-eisen](2N - Fei)-Komplexen 4-6, die spektroskopisch untersucht werden. Die Röntgenstrukturanalyse von 4 beweist das Vorliegen einer linearen Eisen-Nickel-Eisen-Anordnung. Die Kristalle sind triklin, Raumgruppe PT, mit einem Molekül in der Elementarzelle.
    Additional Material: 2 Ill.
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    Zum Mechanismus der Reaktion von 2-Brom-N,N-dimethyl-2, 2-diphenylacetamid mit Natriummethoxid in 2,2-Dimethoxypropan. Eine Methode zum Nachweis des Radikalanion-Radikal-Kettenmechanismus (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3520-3522 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Mechanism of the Reaction of 2-Bromo-N,N-dimethyl-2,2-diphenylacetamide and Sodium Methoxide in 2,2-Dimethoxypropane. A Method for Establishing the Radical-Anion Radical Chain MechanismThermolysis of N,N-dimethyl-2,2-diphenyl-2-(phenylazo)acetamide (1, X = C6H5N≡N-) in the presence of sodium methoxide in 2,2-dimethoxypropane furnishes N,N-dimethyl-2,2-diphenylacetamide (1, X = H), the dimeric product 3, and 2-hydroxymethyl-2,2-diphenylacetamide (1, X = -CH2OH). An analysis of this result leads to the conclusion that the title reaction, which yields compounds 1 (X = H) and 3, is a radical-anion radical chain process.
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    Zinnorganische Verbindungen des 1,2-Diethinylbenzols (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3552-3558 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organo Tin Compounds of 1,2-DiethynylbenzeneThe preparation and the properties of the compounds o-C6H4(C≡C — SnR3)2 (R equals; CH3, C6H5),[o-C6H4(C ≡ C)2SnR2]2 (R = CH3, C6H5, 1-Naphthyl; R2 = Pentamethylene), [o-C6H4(C≡C)2)3-(SnC6H5)2]n (n = 2, 8, 〉8) and [(o-C6H4(C≡C)2)2Sn]n (n = 12-15,〉15) are described. The structures of these compounds are supported by their spectra.
    Notes: Darstellung und Eigenschaften der Verbindungen o-C6H4(C≡C — SnR3)2 (R = CH3 C6H5), [o-C6H4(C≡C)2SnR,sb2]2 (R = CH3, C6H5, 1-Naphthyl; R2 = Pentamethylen), [(o-C6H4(C≡C)2)3-(SnC6H5)2]n (n = 2, 8, 〉8) und [(o-C6H4(C≡C)2)2Sn]n (n = 12-15, 〉15) werden beschrieben. Die Konstitutionen der Verbindungen werden spektroskopisch gestützt.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791121104
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    Beiträge zur Chemie der Cycl[4.3.2]azine (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3577-3588 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Chemistry of Cycl[4.3.2]azines1)6-tert-Butyl-4H-3a-aza-4-azulenone (3c) and the cycl[4.3.2]azine derivatives 1d and e are synthesized. Attempts to eliminate the ester groups of 1d and e by thermolysis failed. Using Fe2(CO)9, 1d and e are transformed into the complexes 9a and b. The thermolysis of 9b yields the anhydride 10. 5-Azacycl[4.3.2]azine-4-carbonic esters 11 are obtained of two independent routes. 12 is prepared from 11 and Fe2(CO)9 -From the NMR spectra it is concluded that a paratropic effect exists of the cycl[4.3.2]azine π-system of about 4-5 ppm being largest in the 7-membered ring. The shifts of all protons are affected by the nitrogen atom in perimeter-position 5 of 11, the maximum effect being observed again in the 7-membered ring.
    Notes: 6-tert-Butyl-4H-3a-aza-4-azulenon (3c) und die Cycl[4.3.2]azin-Derivate 1d und e werden dargestellt. Versuche zur thermolytischen Entfernung der tert-Butoxycarbonylgruppen aus 1d und e scheiterten. Mit Fe2(CO)9 konnten aus 1d e die Tricarbonyleisen-Komplexe 9a und b erhalten werden. Die Thermolyse von 9b führte zum Anhydrid 10. 5-Azacycl[4.3.2]azin-4-carbonsäureester 11 werden auf zwei Wegen dargestellt. Aus 11b wurde der Tricarbonyleisen-Komplex 12 erhalten.  - Die1H-NMR-Spektren weisen auf eine durch das Cycl[4.3.2]azin-π-System verursachte Paratropie von etwa 4-5 ppm, welche im Siebenring am größten ist. Der Einfluß des perimeterständigen Stickstoffatoms auf die chemischen Verschiebungen von 11 erstreckt sich über das gesamte Ringsystem und ist ebenfalls im Siebenring am stärksten ausgeprägt.
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    Polare Cycloadditionen von elektronenreichen Mehrfachbindungssystemen an 1,3,4-Oxadiazolium-Salze: Synthese von 3aH-[1,3,4]Oxadiazolo[3,2-α]chinolinen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3623-3636 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polar Cycloadditions of Electron-rich Multiple Bond Systems to 1,3,4-Oxadiazolium Salts: Synthesis of 3aH-1,3,4 Oxadiazolol 3,2-α quinolinesThe 1,3,4-Oxadiazolium-salts 6c,g,h,i,j react withN,N-Diethyl-1-propin-1-amin(7) in a [4⊕ + 2]-Cycloaddition to afford the 3aH[1,3,4]Oxadiazolo[3,2-a]quinolines 8 c,g,h,i,j.. A [2⊕ + 2] cycloaddition of diethyl acetylenedicarboxylate with 8i yields the tetracycle 9. Alkaline hydrolysis of 8 leads to the quinolone 10. A [3⊕ + 2]-cycloaddition cycloreversion is observed with 6e, I and 18 yielding (→ 12, 15, 20 + 21) respectively. Ketene diethyl acetal (22) reacts with 6k in the same manner (→ 23)
    Notes: Die 1,3,4-Oxadiazolium-Salze 6c,g,h,i,j reagieren mitN,N-Diethyl-1-amin(7) in einer [4⊕ + 2]-Cycloaddition zu den 3aH[1,3,4]Oxadiazolo[3,2-a]chinolinen 8. Eine [2⊕ + 2] Cycloaddition von Acetlylendicarbonsäure-diethylester an 8i führt zum Tetracyclus 9. Die alkalische Hydrolyse von 8 ergibt die Chinolone 10. Eine [3⊕ + 2]-Cycloaddition-Cycloaddition-Cycloreversion wird bei 6e, I und 18 beobachtet (→ 12, 15, 20 + 21). Auch Keten-diethylacetal (22) reagiert mit 6k in dieser Weise (→ 23).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121112
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    Alicyclische Verbindungen, II. Darstellung und Photoelektronenspektren der Cyclopropanierungsprodukte von 3,4-Dimethylen-1-cyclobuten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3691-3702 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alicyclic Compounds, II. Preparation and Photelectron Spectra of the Cyclopropanation Products of 3, 4-Dimethylene-1-cyclobuteneCyclopropanation of 3, 4-Dimethylene-1-cyclobutene (1) with diazomethane/cuprous chloride in pentane provides the novel spiro compounds 6-methylenespiro[2.3]hex-4-ene (2) and dispiro[cyclopropane-1, 2′-bicyclo[2.1.0]pentane-3′, 1″-cyclopropane] 94) as well as the already known dispiro[2.0.2.2]oct-7-ene (3). The photoelectron spectra of these hydrocarbons have been analyzed.
    Notes: Die Cyclopropanierung von 3,4-Dimethylen-1-cyclobuten (1) mit Diazomethan/Kupfer (I) chlorid in Pentan liefert die neuen Spiroverbindungen 6-Methylenspiro [2.3]hex-4-en (2) und Dispiro[cyclopropan-1,2′-bicyclo[2.1.0]pentan-3′,1″-cyclopropan] (4) sowie das bekannte Dispiro [2.0.2.2]oct-7-en (3). Die Photoelektronenspektren dieser Kohlenwasserstoffe werden diskutiert.
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    URL: http://dx.doi.org/10.1002/cber.19791121117
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    Photolyse von Cycloalkeno-1,2,3-thiadiazolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3728-3736 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photolysis of Cycloalkeno-1,2,3-thiadiazolesPhotolysis of the title compounds leads to several types of heterocycles: 1,4-dithiins 5, 1,3-dithioles 9, thiophenes 11, and 1,2,4,5-tetrathianes 12. The yields of the reaction routes 1 - VI depend on the ring size of the cycloalkeno-l,2,3-thiadiazoles (table 1).
    Notes: Bei der Photolyse der Titelverbindungen 1a-d werden Heterocyclen der Typen 1,4-Dithiin 5, 1,3-Dithiol 9, Thiophen 11 und 1,2,4,5-Tetrathian 12 isoliert. Die Ausbeute auf den Reaktionswegen I-VI in Abhängigkeit von der Cycloalkeno-l,2,3-thiadiazol-Ringgröße ist von Interesse (Tab. 1).
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    NMR-Spektroskopische Untersuchungen zur Kinetik und Thermodynamik reversibler Dissoziationsreaktionen, VII. Direkte Beobachtung der Ionisation und Ionenrekombination von Tritylchlorid in SO2 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3715-3722 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR Spectroscopic Studies on Kinetics and Thermodynamics of Reversible Dissoziation Reactions VII. Direct Observation of Ionisation and Ion Recombination of Trityl Chloride in SO2The equilibriaWere analyzed in SO2 by 1H NMR spectroscopy at variable temperature in the partially deuterated compound. The ionisation of trityl chloride into the ion pair was kinetically studied by total line shape analysis of the 1H NMR spectra of the deuterated and the nondeuterated compound. The origin of the relatively high barrier (ΔG1≢ ≈ 42 kJ/mol, ΔS1≢ ≈ -90 J/grad mol) is discussed.
    Notes: Die GleichgewichteIn SO2 wurden in der partiell deuterierten Verbindung durch NMR-Spektroskopie bei variabler Temperatur analysiert. Die Ionisierung des Tritylchlorids in das Ionenpaar wurde durch Linienformanalyse der 1H-NMR-Spektren der deuterierten und nichtdeuterierten Verbindung kinetisch untersucht. Die Ursache der relativ hohen Barrieren (ΔG1≢ = 42 kJ/mol, ΔS1≢ = 25 kJ/mol, ΔS1≢ = - 90 J/grad · mol) wird diskutiert.
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    Diskussion der UV-Spektren von 3-Keto-Δ4,8(14)-Steroiden als Beispiel einer, through space'-Konjugation (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3748-3752 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Discussion of the UV Spectra of 3-keto-Δ4,8(14)-steroids as an Example of a “Through Space” Conjugation
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    Über die Thermolyse von 2-Diazo-1,3-diketonen in Gegenwart von Diazoalkanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3753-3758 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of 2-Diazo-1,3-diketones in the Presence of DiazoalkanesDiazodiketones 1 react with diazoalkanes 3 under the conditions of the Wolff rearrangement via the hypothetical diazonium betaines 4 predominantly by 1,4-cyclization to afford the 3-furanones 11 and enol derivatives 12. Competitively, depending on stabilizing substituents, 1,2-cyclization to the cyclopropanone 6 or the acryl ester 9 as well as cyclization without loss of the diazoalkane nitrogen to the pyrazoles 7, 10 may occur. In the case of electron donating aroylarylketenes the 1,3,4-oxadiazolines 8 are obtained. For the latter reaction, an intermediate azo-zwitterion 5 is assumed.
    Notes: Diazodiketone 1 reagieren mit Diazoalkanen 3 unter den Bedingungen der Wolff-Umlagerung über die hypothetischen Diazoniumbetaine 4 in der Regel durch 1,4-Cyclisierung. wobei 3-Furanone 11 und die Enolderivate 12gebildet werden. Mit dieser Reaktion konkurrieren in Abhängigkeit von stabilisierenden Substituenten: die 1,2-Cyclisierung zum Cyclopropanon 6 bzw. dem Acrylester 9; unter Beibehaltung des Diazoalkan-Stickstoffs Cyclisierung zu den Pyrazolen 7, 10; bei Verwendung elektronenreicher Aroylarylketene schließlich Bildung der 1,3,4-Oxadiazoline 8: Für diesen Reaktionsverlauf wird ein intermediäres Azo-Zwitterion 5 angenommen.
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    Der Einfluß des Dien-1,4-Abstandes auf die Reaktivität bei Diels-Alder-Reaktionen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 883-889 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Significance of Diene-1,4-Distance on the Reactivity in Diels-Alder ReactionsThe reactivity of cyclopentadiene and di-exo-methylene compounds in Diels-Alder reactions is investigated using the frontier molecular orbital method. It is shown that besides the HOMO-LUMO energy difference the diene 1,4-distance plays an important part for the rate of reaction. The shorter this distance is the higher becomes the reactivity. Experimentally this is shown by the rates of reaction of tetracyanoethylene and maleic anhydride with cyclopentadiene and di-exo-methylene compounds 2-6. The 1,4-distance of the latter is known from force field calculations. 1,4-Distance and log k2 exhibit a linear relationship which is supported by theoretical considerations.
    Notes: Die Reaktivität von Cyclopentadien und cis-fixierten Di-exo-methylenverbindungen in Diels-Alder-Reaktionen wird im Rahmen des Grenzorbitalmodells untersucht. Es wird gezeigt, daß neben der Energiedifferenz der dominanten Grenzorbitalwechselwirkung auch der Dien-1,4-Abstand eine wichtige Funktion besitzt. Je kürzer dieser ist, umso reaktiver ist das Dien. Dies zeigt die Kinetik der Umsetzung von Tetracyanethylen und Maleinsäureanhydrid mit Cyclopentadien und den Di-exo-methylenverbindungen 2-6, deren 1,4-Abstand auf Grund von Kraftfeldrechnungen bekannt ist. Zwischen 1,4-Abstand des Diens und log k2 der Cycloaddition besteht ein linearer Zusammenhang, der sich theoretisch begründen läßt.
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    URL: http://dx.doi.org/10.1002/cber.19791120313
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    Der Mechanismus der photolytischen Umsetzung von Pyridin mit Bis(trimethylsilyl)quecksilber, ein Beitrag zur metallorganischen Photochemie (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 950-956 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Mechanism of the Photolytic Reaction of Pyridine with Bis(trimethylsilyl)mercury, a Contribution to the Photochemistry with Metal AlkylsThe photolytic generation of N-(trimethylsilyl)pyridinyls 2 or. resp., their 4,4′-dimers from pyridine or its alkyl derivatives and bis(trimethylsilyl)mercury (1) involves surprisingly no free silyl radicals, but passes a long-lived, photoexcited, polar state 1a of the molecule 1. The latter is described more closely. It is complexed stepwise by two molecules of pyridine, and only in the last step free radicals are formed. The possibly more general importance of these findings for photolytic reactions with metal alkyls is pointed out.
    Notes: Die photolytische Bildung von W-(Trimethylsilyl)pyridinylen 2 bzw. ihren 4.4′-Dimeren. aus Pyridin bzw. seinen Alkylverbindungen und Bis(trimethylsilyl)quecksilber (1) verläuft überraschenderweise nicht über freie Silyl-Radikale, sondern über einen längerlebigen, photoangeregten, polaren Zustand la des Moleküls 1, über den nähere Aussagen gemacht werden. Er wird schrittweise durch zwei Moleküle Pyridin komplexiert, worauf erst im letzten Schritt freie Radikale entstehen. Auf die mögliche Bedeutung der Befunde für andere photolytische Reaktionen mit Metallalkylen wird hingewiesen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120318
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    Cyclopropyl-Nachbargruppeneinfluß auf die Brückenkopfreaktivität von Verbindungen mit Bicyclo[2.2.2]octan-Grundgerüst (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 908-935 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclopropyl Neighbouring Group Influence on the Bridgehead Reactivity of Compounds with a Bicyclo[2.2.2]octane SkeletonUpon photochlorination with tert-butyl hypochlorite the cyclopropane anellated bicyclo[2.2.2]-octane hydrocarbons 10a and 2a-6a give the bridgehead chlorids 10b and 2b-6b in increasing relative yields. In addition, a more efficient directed synthesis for 2b has been developed. The solvolysis reactions of 2b-6b lead to unrearranged bridgehead derivatives exclusively, the substantially increasing rates in the series 2b-6b indicating, that a cyclopropyl group can stabilize a neighbouring carbenium ion center substantially, even if the system does not possess the best bisected conformation. It is only with a perpendicular arrangement of the axis of the carbenium ion p-orbital and the Walsh orbital at the neighbouring cyclopropyl carbon atom as in 10b that the cyclopropyl group exhibits a destabilizing effect exclusively. Analysis of the kinetic parameters leads to the result, that the skeletons of the intermediate carbenium ions from 2b, 5b and 6b are twisted with respect to those of the starting materials, because this apparently enables the intermediates to gain additional stabilization. However, for 3b and 4b the twisting in the ground and the transition state has to be equally small. For 2b and 5b-6b the twist angle decreases with an increasing number of anellated cyclopropane rings. The same conclusions have been drawn from the interpretation of the 13C-chemical shifts of the free bridgehead carbenium ions 2f and 4f-6f, which have been generated by the reaction of the corresponding chlorides with antimony pentafluoride in sulfuryl chloride fluoride.
    Notes: Bei der Photochlorierung mit tert-Butylhypochlorit entstehen aus den cyclopropan-anellierten Bicyclo[2.2.2]octan-Kohlenwasserstoffen 10a und 2a-6a mit ansteigenden Relativanteilen die Brückenkopfchloride 10b und 2b-6b. Die Solvolysereaktionen von 2b-6b führen ausschließlich zu nichtumgelagerten Brückenkopfderivaten; die in dieser Reihe erheblich ansteigenden Geschwindigkeiten - relativ zum 1-Bicyclo[2.2.2]octylchlorid um bis zu 2.8·108. beweisen, daß eine Cyclopropylgruppe auch bei einer von der optimalen bisektierten Anordnung abweichenden Konformation ein benachbartes Carbeniumionzentrum beträchtlich stabilisiert. Nur bei senkrechter Anordnung der Achsen des Carbeniumion-p-Orbitals und des Walsh-Orbitals am benachbarten Dreiring-C-Atom wie in 10b wirkt die Cyclopropylgruppe ausschließlich destabilisierend. Die Auswertung der kinetischen Parameter ergibt, daß die Gerüste der intermediären Carbeniumionen aus 2b, 5b und 6b im Vergleich zu denjenigen der Ausgangsverbindungen stärker verdrillt sind, weil dies offenbar eine zusätzliche Stabilisierung der Zwischenstufen ermöglicht. Bei 3b und 4b dagegen muß die Verdrillung von Ausgangs- und Übergangszustand gleich gering sein; bei 2b, 5b und 6b wird sie mit zunehmender Zahl anellierter Cyclopropanringe geringer. Zu den gleichen Schlußfolgerungen führt die Interpretation der 13C-chemischen Verschiebungen der freien Brückenkopf-Carbeniumionen 2f und 4f-6f, die aus den entsprechenden Chloriden mit Antimonpentafluorid in Sulfurylchloridfluorid erzeugt wurden.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120316
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    Polycarbonylverbindungen, XXIV. Gemischte „Oxothioxokohlenstoffe“ aus Amiden und Thioamiden der Quadratsäure (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 990-999 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycarbonyls, XXIV. Mixed „Oxothioxocarbons“ from Amides and Thioamides of Squaric AcidHydrolysis or sulfhydrolysis of 1,2-or 1,3-Squaric acid diamides or their mono- or dithioderivatives yields sulfur analogues of squaric acid dianion, examples of mixed „oxothioxocarbons“ (5-8). Reaction with electrophiles and nucleophiles as well as spectroscopic data are reported.
    Notes: Durch Hydrolyse bzw. Sulfhydrolyse von 1,2- oder 1,3-Quadratsäurediamiden bzw. ihrer Mono- oder Dithioderivate entstehen Schwefelanaloga des Quadratsäure-Dianions, Vertreter der gemischten „Oxothioxokohlenstoffe“ (5-8). Es werden Reaktionen mit Elektrophilen und Nucleophilen beschrieben und spektroskopische Daten mitgeteilt.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120321
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    Cycloadditionsreaktionen von Heterocumulenen, XVII. Über den Mechanismus der [2+2]-Cycloaddition von Thioketenen mit Azomethinen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1000-1011 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of Heterocumulenes, XVII. On the Mechanism of the [2+2]-Cycloaddition of Thioketenes with AzomethinesThe thioketene 1 reacts with the azomethines 2a-f to give the β- thiolactames 3a-f, the structures of which were proven by methylation and oxidation leading to 7 and 8/9c Attempts to trap the potential intermediate of the cycloaddition 11 were unsuccessful. Kinetic experiments demonstrate low solvent and substituent effects on the cycloaddition rate. Starting form 1-deuterated and 1-undeuterated 2b a secondary kinetic isotope effect was measured. These results as well as the formation of the sterically disfavoured cycloadduct 3A indicate that in the rate-determining step of the cycloaddition not the „classical“ dipole 11 is formed, but with orbital symmetry -control the dipolar species 14.
    Notes: Das Thioketen 1 reagiert mit den Azomethinen 2a - zu den β-Thiolactamen 3a-f, deren Struktur durch Methylierung zu 7 und Oxidation zu 8/9c belegt wurde. Versuche, die potentielle Zwischenstufe der Cycloaddition 11 abzufangen, verliefen negativ. Nach kinetischen Untersuchungen sind Lösungsmittel-und Substituenteneinflüsse auf die Cycloadditionsgeschwindigkeit gering. Ausgehend von 1-deuteriertem und 1-undeuteriertem 2b wurde ein sekundärer Isotopeneffekt gemessen. Diese Ergebnisse wie auch die Bildung des sterisch ungünstigen Cycloaddukts 3A sprechen dafür, daß im geschwindigkeitsbestimmenden Schritt der Cycloaddition kein „klassischer“ Dipol 11 entsteht, sondern unter Orbitalsymmetrie-Kontrolle die dipolare Species 14.
    Additional Material: 4 Tab.
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    Thiirene als Zwischenstufen der Thermolyse von 1,2,3-Thiadiazolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1769-1778 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiirenes as Intermediates in the Thermolysis of 1,2,3-ThiadiazolesThermolysis of the isomeric thiadiazoles 1a or 1b in moist 2,2′-oxydiethanol (3) yields the ketone 6, the thiophene 7, the alkyne 8, and the disulfide 11, the structure of which was determined by an X-ray analysis. In the presence of diphenylacetylene (15) 1a and 1b react to give the thiophenes 16a and 16b in the same ratio. This implies that the primary products of thermolysis, the 1,3-diradicals 13, can be trapped by alkynes. The formation of identical thiophenes from isomeric thiadiazoles 1 can be understood in terms of an equilibrium between the primary fragments 13 via the thiirene 14. Similarly, the ketone 6 seems not to result from 8 but from 14.
    Notes: Bei der Thermolyse der stellungsisomeren Thiadiazole 1a oder 1b in feuchtem 2,2′-Oxydiethanol (3) entstehen das Keton 6, das Thiophen 7, das Alkin 8 und das durch eine Röntgenstrukturanalyse eindeutig aufgeklärte dimere Disulfid 11. In Gegenwart von Diphenylacetylen (15) bilden sich aus 1a und 1b die Thiophene 16a und 16b im selben Verhältnis. Die bei der Thermolyse zunächst entstehenden 1,3-Diradikale 13 können demnach durch Alkine abgefangen werden. Die Bildung identischer Thiophene aus isomeren Thiadiazolen 1 läß sich durch ein Gleichgewicht der Primärfragmente 13 verstehen, das sich über das Thiiren 14 einstellt. Auch das Keton 6 scheint nicht aus 8, sondern aus 14 zu entstehen.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120528
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    Neue helicale Kohlenwasserstoffe, III. Pentaphenylenicene (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1785-1790 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Helical Hydrocarbons, III. PentaphenylenicenesSynthesis and properties of o,p-bridged quinquephenyl compounds 5, 6 are reported. The 1H NMR highfield shift of H1 and the temperature independence of some absorptions are interpreted in terms of a more fixed helical arrangement of the o,p-compared with the m,m-bridged compound 4. p-Phenylene rotation as well as plus-minus interconversion are not observed.
    Notes: Synthese und Eigenschaften der endständig in o,p-Stellung verbrückten Quinquephenyl-Verbindungen 5, 6 werden beschrieben. Die 1H-NMR-Hochfeldverschiebungen von H1 und die Temperaturunabhängigkeit einzelner Absorptionen weisen darauf hin, daß die o,p-Verbrückung zu deutlich stärker fixierten Helices führt als die m,m-Klammer in 4. Eine p-Phenylenrotation wird ebensowenig wie eine Plus-Minus-Umwandlung beobachtet.
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    URL: http://dx.doi.org/10.1002/cber.19791120530
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    Pyrane, 78. Über Reaktionen von 3-Formylchromonen mit Diphenylketen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1791-1807 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pyrans, 78. Reactions of 3-Formylchromones with DiphenylketeneThe reaction of 3-formylchromones 3a und b with diphenylketene (1) leads to 3-(diphenylvinyl)-chromones 2a and b as well as to the diphenyl-tetrahydropyrano[4,3-b]benzopyrandiones 4a and b. Treatment with base converts 4 into 2. With nucleophilic reagents 2 and 4 give rise to diphenylvinyl-substituted ketones (9), enamines (11), pyrazoles(10), pyrimidines (12), and 1,5-benzodiazepines (13) as well as to chromanonyl-diphenyl-acetic acid dervatives (16 and 18), benzopyrano[3,2-c]pyridines (21), to benzopyrano[4,3-c]pyrazole and -isoxazole derivatives (22).
    Notes: Die 3-Formylchromone 3a und b reagieren mit Diphenylketen (1) zu den 3-(Diphenylvinyl)- chromonen 2a und b sowie den Diphenyltetrahydropyrano[4,3-b]benzopyrandionen 4a und b. 4 läßt sich mit Basen in 2 überführen. Mit nucleophilen Reagenzien setzen sich 2 und 4 zu diphenylvinyl-substituirten Ketonen (9), Enaminen (11), Pyrazolen (10), Pyrimidinen (12) und 1,5-Benzodiazepinen (13) um sowie zu Chromanonyl-diphenyl-essigsäure-Derivaten (16 und 18), Benzopyrano[3,2-c]pyridinen (21), zu Benzopyrano[4,3-c]pyrazol- und -isoxazol-Derivaten (22).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120531
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    Cycloadditionen von Cyanthioformamiden mit 1,3-Dipolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1873-1878 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloadditions of Cyanothioformamides with 1,3-DipolesThe disubstituted cyanothioformamides 1 add to diazo compounds presumably forming the thiadiazoles 2 which decompose to give the thiiranes 3. These may be desulfurized to the ethylenes 5.1b reacts with diphenylnitrilimine to form the thiadiazoline 6. Nitrile oxides and 1 afford the oxathiazoles 7. The monosubstituted cyanothiaoformamides 8. likewise yield the oxathiazoles 9. which decompose to aryl isothiocyanates and the cyanoformamides 10. The reaction of 1 with phenylazide at 100°C produces the cyanoformamidines 14. probably via the unstable thiatriazolines 11 or 12 and the thiaziridines 13.
    Notes: Die disubstituierten Cyanthioformamide 1 addieren sich an Diazoverbindungen, vermutlich unter Bildung der Thiadiazole 2, die weiter zu den Thiiranen 3 zerfallen. Diese können zu den Ethylenen 5 entschwefelt werden. Mit Diphylnitrilimin bildet 1b das Thiadiazolin 6. Nitriloxide liefern mit 1 die Oxathiazole 7. In gleicher Weise ergeben die monosubstituierten Cyanthioformamide 8 die Oxathiazole 9, die weiter in Arylisothiocyanate und die Cyanformamide 10 zerfallen. Die Reaktion von 1 mit Phenylazid bei 100°C liefert, offenbar über die instabilen Thiatriazoline 11 oder 12 und die Thiaziridine 13, die Cyanformamidine 14.
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    Reaktionen an Indolderivaten, XXXVIII. Dreiringreaktionen in der Indolreihe (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1889-1901 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XXXVIII. Cyclopropane Reactions in the Indole SeriesThe acid-catalyzed and the nucleophilic ring-opening of the cyclopropanelactams 1 and 2 studied and their stereospecifity is reported. The ketolactams 22 and 23 obtained via this route represent important intermediates.
    Notes: Die protonenkatalysierte und die nucleophile Ringöffnung der Cyclopropanlactame 1 und 2 werden studiert und die Stereospezifität beschrieben. Die auf diese Weise erhaltenen Ketolactame 22 und 23 sind wichtige Zwischenprodukte.
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    Reaktionen an Indolderivaten XXXVII. Stereoselektive Synthese polycyclischer Cyclopropanderivate in der Indolochinolizin-Reihe (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1879-1888 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XXXVII. Stereoselective Synthesis of Polycyclic Cyclopropane Derivatives in the Indoloquinolizine SeriesThe high yield stereoselective synthesis of the pentacyclic cyclopropanelactam 8 is reported.
    Notes: Es wird über eine in guten Ausbeuten verlaufende stereoselektive Synthese des pentacyclischen Cyclopropanlactams 8 berichtet.
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    Reaktionen an Indolderivaten, XL. Ein einfacher Zugang zum Yohimbenon (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1913-1915 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions with Indole Derivatives, XL. Simple Access to YohimbenoneThe enolether 1, obtained by Birch reduction, easily and in high yield gives rise to yohimbenone (6) via hydrolysis followed by formaldehyde cyclization.
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    URL: http://dx.doi.org/10.1002/cber.19791120542
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    Neue μ-Hydroxo-Übergangsmetallkomplexe, II. Darstellung mehrkerniger Komplexe des Chroms(III) mit dreizähnigen Amin-Liganden. Struktur des μ[cis-Dihydroxo(O,O′)-hydroxo(l,4,7-triazacyclononan)chrom(III)]-di-μ-hydroxobis[(1,4,7-triazacyclononan)chrom(III)]-Kations (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2837-2846 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel μ-Hydroxo-Transition Metal Complexes, II. Preparation of Polynuclear Complexes of Chromium(III) Containing Tridentate Amine Ligands. The Structure of the μ-[cis-Dihydroxo(O,O′)-hydroxo(l,4,7-triazacyclononane)chromium(III)]-di-μ-hydroxo-bis[(1,4,7-triaacyziononane)chromium(III)] CationThe attempted preparation of dinuclear complexes of chromium(III) containing three μ-hydroxo bridges by a condensation reaction of triaquaaminechromium(III) complexes [amine = 1,1,1-tris(aminomethyl)ethane (l) or l,4,7-triazacyclononane (2)] in acidic media yields only di-μ-hydroxo-bis[aquaaminechromium(III)] complexes (3, 4). More drastic reaction conditions afford a trinuclear complex 7 containing four μ-hydroxo bridges and a terminal OH-ligand which is linked to one μ-hydroxo bridge via a very short hydrogen bond contributing substantially to the stability of this cation. A single-crystal X-ray analysis of [Cr3([9]aneN3)3(OH)5]I5 · 5H2O (8) exhibits two different pairs of μ-hydroxo bridges with bond angles of 98 and 126°, respectively. The synthesis of a dinuclear, triply hydroxobridged chromium(III) complex has not been successful.
    Notes: Versuche, zweikernige Komplexe des Chroms(III) mit drei μ-Hydroxobrücken durch Kondensation von Triaquaaminchrom(III)-Komplexen [Amin = 1,1,1-Tris(aminomethyl)ethan (1) Oder 1,4,7-Triazacyclononan (2)] in saurem Medium darzustellen, führen nur zu Di-μ-hydroxo-bis-[aquaaminchrom(III)]-Komplexen (3, 4). Drastischere Reaktionsbedingungen führen zur Bildung eines dreikernigen Komplexes 7 mit vier μ-Hydroxobrücken und einer terminalen OH-Gruppe, die  -  gebunden über eine starke H-Brückenbindung zu einer μ-Hydroxobrücke  -  wesentlich zur Stabilität dieses Kations beiträgt. Eine Röntgenstrukturanalyse von [Cr3([9]anN3)3(OH)5]I5. 5 H2O (8) zeigt die Existenz zweier unterschiedlicher Paare von μ-Hydroxobrücken in dem dreikernigen Kation mit -Bindungswinkeln von 98 bzw. 126°. Die Synthese eines zweikernigen Tri-μ-hydroxo-Komplexes des Chroms(III) gelang nicht.
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    URL: http://dx.doi.org/10.1002/cber.19791120810
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    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590101
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    The structure and distribution of external sense organs in newly hatched and mature earthworms (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 1-15 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fully mature adult Eisenia foetida sensory buds are abundant on the prostomium and the first segment. In subsequent segments they are restricted to the anterior half where they form a single row aligned with the setae and encircling the worm. In the more posterior regions of the worm the buds are widely separated and fewer. The surface of each bud is a raised circular or oval area from which 15 to 100 so-called sensory hairs arise, being cylindrical and apparently flexible. The number of these projections decreases toward the posterior end of the worm.In worms newly emerged from egg cocoons, the general pattern of distribution and external form of sensory buds resembles that of adults, but the buds are much fewer and smaller than in adults. Although these worms emerge with their definitive adult number of segments, new buds and additional sensory projections are formed during post hatching development.
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