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  • Inorganic Chemistry  (15,232)
  • Biology
  • Ertrag
  • Hafer
  • LUNAR AND PLANETARY EXPLORATION
  • 2020-2024  (19)
  • 2010-2014  (26)
  • 1970-1974  (4,337)
  • 1935-1939  (3,375)
  • 1930-1934
  • 1925-1929
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  • 1
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    Was sind Gene nicht? (2024)
    transcript Verlag | transcript Verlag
    Details
    Publication Date: 2024-03-22
    Description: Gene gelten im Allgemeinen als die Essenz eines Lebewesens, die all seine charakteristischen Eigenschaften bestimmt. Aus biologischer Sicht trifft diese Vorstellung jedoch längst nicht mehr zu. Im Mittelpunkt dieses Buches steht daher die Frage, warum und wie das essentialistische Denken die gesellschaftliche Wahrnehmung biologischer Forschungsprojekte immer noch beeinflusst. Anhand aktueller Erkenntnisse der Genetik und Epigenetik geht Kirsten Schmidt auf die Suche nach einer neuen Interpretation des Genbegriffs im Zeitalter der Postgenomik. Das Verständnis von Genen als dynamischen Prozessen erweist sich dabei als eine fruchtbare Alternative zum Essentialismus.
    Keywords: Essentialismus ; Gen ; Philosophie ; Epigenetik ; Biologie ; Genetik ; Postgenomik ; Leben ; Wissenschaft ; Wissenschaftsphilosophie ; Naturphilosophie ; Wissenschaftssoziologie ; Soziologie ; Philosophy ; Biology ; Life ; Science ; Philosophy of Science ; Philosophy of Nature ; Sociology of Science ; Sociology ; bic Book Industry Communication::P Mathematics & science::PD Science: general issues::PDA Philosophy of science ; bic Book Industry Communication::H Humanities::HP Philosophy::HPJ Philosophy: metaphysics & ontology ; bic Book Industry Communication::P Mathematics & science::PD Science: general issues::PDR Impact of science & technology on society
    Language: German
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  • 2
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    Dějiny Biologického ústavu Lékařské fakulty Masarykovy univerzity (2023)
    Masaryk University Press | Masaryk University
    Details
    Publication Date: 2024-04-04
    Description: Title in English: History of the Institute of Biology, Faculty of Medicine, Masaryk University A representative book on the history and present of one of the oldest institutes of the Faculty of Medicine of Masaryk University, which has been contributing significantly to the development of biological sciences since its inception.
    Keywords: Historical sciences ; Historyof Medicine ; health care ; Personalities ; Natural science ; Biology ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science
    Language: Czech
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  • 3
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    Experimentierprozesse von Lehramtsstudierenden der Biologie -- Eine Videostudie (2022)
    Logos Verlag Berlin | Logos Verlag Berlin
    Details
    Publication Date: 2024-04-04
    Description: In Zeiten, in denen die Komplexität gesellschaftlicher, politischer, wirtschaftlicher und technologischer Probleme zunehmend steigt, ist der Erwerb einer naturwissenschaftlichen Grundbildung für die persönliche Meinungsbildung von zentraler Bedeutung. Hierzu gehört das Erlernen von naturwissenschaftlichen Erkenntnismethoden wie dem Experimentieren. Erkenntnisse zu experimentierspezifischen Kompetenzen zeigen, dass Lernende über unterschiedliche Vorstellungen bezüglich des Experimentierens verfügen. Diese zeigen sich in unterschiedlichen Vorgehensweisen, die mehr oder weniger stark von der Vorgehensweise in realer wissenschaftlicher Forschung abweichen. Ziel der vorliegenden Studie ist eine differenzierte Erfassung und Analyse individueller Prozessstrukturen sowie prozessbezogener Niveaustufen von Experimentierprozessen Lehramtsstudierender der Biologie. Die Ergebnisse zeigen, dass die meisten Experimentierprozesse nicht, wie in idealisierten Modellen angenommen, einem linearen Prozessverlauf verlaufen, sondern wiederholte Wechsel zwischen den Experimentierphasen aufweisen. Insbesondere die Durchführung nimmt hier eine zentrale Stellung ein. Die Vernetzung der Experimentierphasen ist unterschiedlich ausgeprägt und steht in einem positiven Zusammenhang mit der Qualität eines Experimentierprozesses. Die prozessbezogenen Niveaustufen weisen Ausprägungen über alle Niveaus hinweg auf. Aus den Ergebnissen werden Hinweise zur Gestaltung von Unterricht und universitärer Lehre sowie Implikationen für die fachdidaktische Forschung abgeleitet.
    Keywords: Science ; Science ; Life Sciences ; Biology ; Education ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences ; thema EDItEUR::J Society and Social Sciences::JN Education
    Language: German
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  • 4
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    The Blurring of Boundaries in Bioscientific Discourse (2022)
    Logos Verlag
    Details
    Publication Date: 2024-04-05
    Description: New technologies have revealed previously unknown and invisible parts of the human body and made it visible at the molecular level, revealing in turn more detailed structures and arrangements than those which were previously available. In doing so, in many ways they refine, expand, and even completely overturn forms of contemporary knowledge. This book maps the shifts and blurring of boundaries in contemporary bioscientific discourse. The authors of its chapters trace the shifts of boundaries in terms of the gradual blurring of the validity of established concepts, interpretive frameworks, and standards of judgment, which are analysed from ontological, gnoseological, ethical, and social perspectives. At the same time, they also map the blurring of boundaries in terms of the interdisciplinary crossing of boundaries between various scientific and artistic disciplines. The shifting of boundaries ultimately forms a part of these boundaries’ definition; upon the basis of a rationally guided discussion, these shifts can be guided and corrected so as to avoid any irreversible damage. Jana Tomašovičová is a philosopher with a special interest in contemporary philosophy and bioethics. She analyses the impact of biotechnology on traditional social, ethical, and anthropological concepts and their relevance in new conditions. She is an associate professor at the Faculty of Arts, University of Ss. Cyril and Methodius in Trnava, Slovakia. During her bioethics research, she conducted short research stays at the universities of Bonn, Heidelberg, Tübingen, and Zürich.
    Keywords: Science ; Life Sciences ; Biology ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences
    Language: English
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  • 5
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    The Endangered Species Act (2021)
    Taylor & Francis | CRC Press
    Details
    Publication Date: 2023-09-12
    Description: The complex regulations of the Endangered Species Act established by the U.S. Fish and Wildlife Service can be challenging for environmental professionals who must comply with them or assist clients in compliance. This is true especially for those without a background in biology or ecology. The Endangered Species Act: History, Implementation, Successes, and Controversies discusses the Act using clear scientific prose that all professionals whose activities fit into the ESA compliance process can readily comprehend, including those with limited education in science. The book begins by exploring the deeply rooted history of the Endangered Species Act, which extends back decades preceding its enactment in 1973. It continues with a discussion of the basic scientific theory underlying the Act and provides an overview of its key regulations. The author also examines the Act in the context of other key environmental planning statutes such as the National Environmental Policy Act and the Clean Water Act, especially Section 404 of the Clean Water Act, which relates specifically to wetlands. The remainder of the book details the regulatory processes faced by other government agencies and private developers who must routinely ensure that their actions comply with the Endangered Species Act. It concludes with a broad discussion of current controversies associated with the Act and how those controversies might ultimately change how environmental practitioners will have to comply with the Act in the future. The book is neither a defense of the Endangered Species Act and its associated regulations nor a call to repeal or modify the Act or regulations. The presentation is factual and avoids the hype and hyperbole commonly directed at the Act by both environmental activists and deregulation proponents. Readers will gain a solid understanding of how the Act was established, what goals were envisioned by its framers, how current environmental practice under the Act has been shaped, and how those practices might be changed in the future.
    Keywords: Environment law ; Applied ecology ; Biology ; life sciences ; Zoology & animal sciences ; bic Book Industry Communication::L Law::LN Laws of Specific jurisdictions::LNK Environment, transport & planning law::LNKJ Environment law ; bic Book Industry Communication::R Earth sciences, geography, environment, planning::RN The environment::RNC Applied ecology ; bic Book Industry Communication::P Mathematics & science::PS Biology, life sciences ; bic Book Industry Communication::P Mathematics & science::PS Biology, life sciences::PSV Zoology & animal sciences
    Language: English
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  • 6
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    Bloomsbury Scientists (2021)
    UCL Press
    Details
    Publication Date: 2024-03-23
    Description: Bloomsbury Scientists is the story of the network of scientists and artists living in a square mile of London before and after the First World War. This inspired group of men and women viewed creativity and freedom as the driving force behind nature, and each strove to understand this in their own inventive way. Their collective energy changed the social mood of the era and brought a new synthesis of knowledge to ideas in science and art. Class barriers were threatened as power shifted from the landed oligarchy to those with talent and the will to make a difference. A time of unexpected opportunities, from the new disciplines of Genetics and Ecology to Post-Impressionism and beyond, Michael Boulter seamlessly weaves together the stories originating from Bloomsbury’s laboratories, libraries and studios. He narrates the breakthroughs of scientists such as Ray Lankester and Marie Stopes alongside the creative outputs of H. G. Wells and Virginia Woolf, among many others, and intricately connects them all through personal friendships, grievances, quarrels and affections. Bloomsbury Scientists offers a fresh and crucial perspective on this history at a time when the complex relationship between science and art continues to be debated.
    Keywords: london ; history of science ; bloomsbury ; scientists ; Biology ; Charles Darwin ; Evolution ; Francis Galton ; thema EDItEUR::1 Place qualifiers::1D Europe::1DD Western Europe::1DDU United Kingdom, Great Britain ; thema EDItEUR::N History and Archaeology::NH History::NHD European history ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science
    Language: English
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  • 7
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    Polyoxometalates in Catalysis, Biology, Energy and Materials Science (2021)
    Frontiers Media SA
    Details
    Publication Date: 2024-04-04
    Description: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact
    Keywords: polyoxometalates ; Catalysis ; Biology ; Energy ; Materials Science ; magnetic materials ; active matter ; Water-oxidation ; Keggin ; supramolecular chemistry ; thema EDItEUR::P Mathematics and Science::PD Science: general issues
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  • 8
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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
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  • 9
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    Nanofibres: Friend or Foe? (2021)
    MDPI - Multidisciplinary Digital Publishing Institute
    Details
    Publication Date: 2024-04-05
    Description: Nanofibers, particularly those of a carbonaceous content, have received increased interest in the past two decades due to their outstanding physico-chemical characteristics and their possibility to form and contribute towards a plethora of potentially advantageous materials for consumer, industrial and medical applications. Despite this, and together with the numerous research studies and published articles that have sought to investigate these aspects, the potential impact of CNTs is still not understood. Whether or not nanofibers may be able to provide a sophisticated alternative to conventional materials is still debatable, whilst their effects upon both environmental and human health are highly equivocal. How nanofibers are conceived can determine how they may interact with different environments, such as the human body. Understanding each key step of the synthesis and production of nanofibers to their use within potential applications is therefore essential in gaining an insight into how they may be perceived by any biological system and environment. Thus, obtaining such information will enable all scientific communities to begin to realize the potential advantages posed by nanofibers. The aim of this Special Issue therefore, was to provide a collective overview of nanofibers; ‘from synthesis to application’. The Issue particularly focuses upon carbon-based nanofibers, but also highlights alternative nanofiber types. Emphasis is given holistically, with articles discussing the production routes of nanofibers, their plight during their life-cycle (origin to applied form and effects over time), as well as how nanofibers could either incite conflict, or provide aid to human and environmental health.
    Keywords: QD1-999 ; Toxicology ; Chemistry ; Biology ; Material Science ; Nanofibers ; Nanotechnology ; thema EDItEUR::P Mathematics and Science::PN Chemistry
    Language: English
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  • 10
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    Wahrnehmung - Kognition - Ästhetik (2021)
    transcript Verlag
    Details
    Publication Date: 2021-02-10
    Description: Wahrnehmung, Kognition und Ästhetik lassen sich als differente Verarbeitungs- und Ausdrucksformen einer biologischen Basisausstattung des Menschen verstehen. Ob diese stabil sind oder ob sie kulturell überformt oder gar transformiert werden, bildet die zentrale medienanthropologische Fragestellung des Bandes. Dabei wird geprüft, welcher Art die wechselseitigen Impulse sind, die zu kulturellen und biologischen Veränderungen führen können, welche Wirkung sie besitzen und welche Dauer ihnen zukommt. Diese Fragen richten sich nicht allein auf Prozesse wahrnehmungstechnischer, kognitiver oder ästhetischer Habitualisierungen, sondern thematisieren deren physiologische Voraussetzungen. Mit der Beteiligung ausgewiesener Forscher aus den Bereichen Biologie, Medizin und Hirnforschung erschließt dieser Band Neuland im Grenzgebiet der Natur- und Kulturwissenschaften.
    Keywords: Wahrnehmung ; Kognition ; Ästhetik ; Medien ; Biologie ; Hirnforschung ; Medienästhetik ; Medienwissenschaft ; Aesthetics ; Media ; Biology ; Media Aesthetics ; Media Studies ; bic Book Industry Communication::J Society & social sciences::JF Society & culture: general::JFD Media studies
    Language: German
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  • 11
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    The Szczecin Lagoon Ecosystem. The Biotic Community of the Great Lagoon and its Food Web Model (2021)
    De Gruyter
    Details
    Publication Date: 2024-04-05
    Description: The Great Lagoon is a central part of the Szczecin Lagoon, a major component in the Odra River estuary system. It is also an important European natural heritage site and one of the largest resting places for migratory birds in the Baltic Sea area. The first part of Wolnomiejski's and Witek’s book gives a thorough overview of the most up-to-date knowledge of this region, including the assessment of its biological production. Based on these findings authors develop a food web model of the Polish part of the Szczecin Lagoon, identifying a total of 45 trophic-functional components. The model describes a variety of features ranging from the magnitude of consumption, to the amount of unassimilated food and export of individual system components, and serves as an invaluable source, helping researchers to estimate various ecological indicators of The Great Lagoon’s ecosystem.
    Keywords: QH301-705.5 ; Biology ; Natural Sciences ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences
    Language: English
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  • 12
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    Johann Friedrich Blumenbach (2021)
    Universitätsverlag Göttingen
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    Publication Date: 2024-04-04
    Description: This bibliography documents the printed works of Johann Friedrich Blumenbach (1752–1840) and makes them accessible for research purposes. Blumenbach was Professor of Medicine and Natural History at the University of Göttingen. He was one of the leading exponents of the revolutionary change of the geo-biological concept of the world at the turn of the 18th to the 19th century. His works exemplarily show the interactions between the life sciences, the humanities and the social sciences of his day.
    Keywords: History of Universities ; Bibliography ; Biology ; History of Science ; Darwinism ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education::JNM Higher education, tertiary education ; thema EDItEUR::G Reference, Information and Interdisciplinary subjects::GB Encyclopaedias and reference works::GBC Reference works::GBCR Bibliographies, catalogues ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science
    Language: German
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  • 13
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    A more developed sign: interpreting the work of Jesper Hoffmeyer (2021)
    University of Tartu Press
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    Publication Date: 2022-04-28
    Description: For more than 40 years, Jesper Hoffmeyer has been committed to the idea of developing “a semiotics of nature, or biosemiotics as he chose to call this effort, that could intelligibly explain how all the phenomena of inherent meaning and signification in living nature – from the lowest level of sign processes in unicellular organisms to the cognitive and social behavior of animals – can emerge from a universe that was not so organized and meaningful from the very beginning” (Emmeche et al. 2002: 41). In this volume, over 80 world-class scholars from more than 20 countries select a short quotation taken from any of Jesper Hoffmeyer’s texts and provide their scholarly commentary upon that passage – whether in the form of an analytical explication, a critical disagreement or a conceptual extension – that as they feel asks the questions that need to be asked, proposes the ideas that need to be proposed, or that draws out the implications that need to be so explicitly drawn out, germane to the claims of the selected passage. At once a celebration and a serious academic development of the work of Jesper Hoffmeyer, this landmark volume marks the occasion of his 70th birthday on February 21, 2012.
    Keywords: jesper hoffmeyer ; semiotics ; biosemiotics ; Biology ; Charles Sanders Peirce ; Evolution ; Semiosis ; bic Book Industry Communication::G Reference, information & interdisciplinary subjects::GT Interdisciplinary studies::GTE Semiotics / semiology
    Language: English
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  • 14
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    Plastidules to Humans - Leopoldo Maggi (1840-1905) and Ernst Haeckel´s naturalist philosophy in the Kingdom of Italy (2021)
    Universitätsverlag Göttingen
    Details
    Publication Date: 2024-04-08
    Description: The name DGGTB (Deutsche Gesellschaft für Geschichte und Theorie der Biologie; German Society for the History and Theory of Biology) reflects recent history as well as German tradition. The Society is a relatively late addition to a series of German societies of science and medicine that began with the »Deutsche Gesellschaft für Geschichte der Medizin und der Naturwissenschaften«, founded in 1910 by Leipzig University's Karl Sudhoff (1853-1938), who wrote: »We want to establish a ,German' society in order to gather German-speaking historians together in our special disciplines so that they form the core of an international society...«. Yet Sudhoff, at this time of burgeoning academic internationalism, was »quite willing« to accommodate the wishes of a number of founding members and »drop the word German in the title of the Society and have it merge with an international society«. The founding and naming of the Society at that time derived from a specific set of historical circumstances, and the same was true some 80 years later when in 1991, in the wake of German reunification, the »Deutsche Gesellschaft für Geschichte und Theorie der Biologie« was founded. From the start, the Society has been committed to bringing studies in the history and philosophy of biology to a wide audience, using for this purpose its Jahrbuch für Geschichte und Theorie der Biologie. Parallel to the Jahrbuch, the Verhandlungen zur Geschichte und Theorie der Biologie has become the by now traditional medium for the publication of papers delivered at the Society's annual meetings. In 2005 the Jahrbuch was renamed Annals of the History and Philosophy of Biology, reflecting the Society's internationalist aspirations in addressing comparative biology as a subject of historical and philosophical studies.
    Description: The name DGGTB (Deutsche Gesellschaft für Geschichte und Theorie der Biologie; German Society for the History and Theory of Biology) reflects recent history as well as German tradition. The Society is a relatively late addition to a series of German societies of science and medicine that began with the »Deutsche Gesellschaft für Geschichte der Medizin und der Naturwissenschaften«, founded in 1910 by Leipzig University's Karl Sudhoff (1853-1938), who wrote: »We want to establish a ,German' society in order to gather German-speaking historians together in our special disciplines so that they form the core of an international society...«. Yet Sudhoff, at this time of burgeoning academic internationalism, was »quite willing« to accommodate the wishes of a number of founding members and »drop the word German in the title of the Society and have it merge with an international society«. The founding and naming of the Society at that time derived from a specific set of historical circumstances, and the same was true some 80 years later when in 1991, in the wake of German reunification, the »Deutsche Gesellschaft für Geschichte und Theorie der Biologie« was founded. From the start, the Society has been committed to bringing studies in the history and philosophy of biology to a wide audience, using for this purpose its Jahrbuch für Geschichte und Theorie der Biologie. Parallel to the Jahrbuch, the Verhandlungen zur Geschichte und Theorie der Biologie has become the by now traditional medium for the publication of papers delivered at the Society's annual meetings. In 2005 the Jahrbuch was renamed Annals of the History and Philosophy of Biology, reflecting the Society's internationalist aspirations in addressing comparative biology as a subject of historical and philosophical studies.
    Keywords: Biology ; Historical studies ; Philosophical studies ; Maggi ; Pavia ; bic Book Industry Communication::H Humanities::HP Philosophy::HPC History of Western philosophy ; bic Book Industry Communication::P Mathematics & science::PS Biology, life sciences ; bic Book Industry Communication::W Lifestyle, sport & leisure::WN Natural history ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDH Philosophical traditions and schools of thought ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences ; thema EDItEUR::W Lifestyle, Hobbies and Leisure::WN Nature and the natural world: general interest
    Language: German
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  • 15
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    Education and Ethics in the Life Sciences: Strengthening the Prohibition of Biological Weapons (2021)
    ANU Press
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    Publication Date: 2022-04-28
    Description: At the start of the twenty-first century, warnings have been raised in some quarters about how – by intent or by mishap – advances in biotechnology and related fields could aid the spread of disease. Science academics, medical organisations, governments, security analysts, and others are among those that have sought to raise concern. Education and Ethics in the Life Sciences examines a variety of attempts to bring greater awareness to security concerns associated with the life sciences. It identifies lessons from practical initiatives across a wide range of national contexts as well as more general reflections about education and ethics. The eighteen contributors bring together perspectives from a diverse range of fields – including politics, virology, sociology, ethics, security studies, microbiology, and medicine – as well as their experiences in universities, think tanks and government. In offering their assessment about what must be done and by whom, each chapter addresses a host of challenging practical and conceptual questions. Education and Ethics in the Life Sciences will be of interest to those planning and undertaking training activities in other areas. In asking how education and ethics are being made to matter in an emerging area of social unease, it will also be of interest to those with more general concerns about professional conduct.
    Keywords: biotechnology ; prevention ; ethics ; education ; Bioethics ; Biological warfare ; Biological Weapons Convention ; Biology ; Biosecurity ; China ; Dual-use technology ; bic Book Industry Communication::J Society & social sciences::JF Society & culture: general::JFM Ethical issues & debates::JFMG Ethical issues: scientific & technological developments ; bic Book Industry Communication::J Society & social sciences::JN Education
    Language: English
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  • 16
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    Chapter 13 The value of the imagined biological in policy and society (2021)
    Taylor & Francis | Routledge
    Details
    Publication Date: 2024-04-07
    Description: Attending the World Economic Forum this past week, I was struck by two trends. The first was that brain research has emerged as a hot topic. Not only was brain science or brain health a new theme at the meeting, research on the brain emerged in discussions about next generation computing, global cooperation, and even models of economic development as well as being linked to mental health or mindfulness. In a meeting frequented largely by economists and business leaders, I was surprised by the number of non-scientists who have become enchanted by brain science. Clearly this is the era of the brain, with mental health now part of a much broader discussion.
    Keywords: policy ; society ; mental health ; Biology ; Epigenetics ; Genetics ; Genome ; Neuroscience ; Plastic ; Social policy ; thema EDItEUR::J Society and Social Sciences ; thema EDItEUR::M Medicine and Nursing
    Language: English
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  • 17
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    Visões da Luz (2021)
    Coimbra University Press
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    Publication Date: 2022-01-31
    Description: This work brings together various contributions from experts in very diverse areas of knowledge, to discuss the theme ‘Light’ from various points of view. The subjects gathered in this work come from the areas of Physics, Philosophy, Transcendence, Chemistry, Optics, Literature, History of Sciences, History, Geography, International Relations, Biology, Psychology, Art, Cinema and Photography, Medicine and Museology. The texts partially reflect the contents presented at the interdisciplinary colloquium ‘Visões da Luz’ held in October 2015, on the occasion of the International Year of Light 2015, under the aegis of III-UC and open to academia and society, to teachers of the Basic and Secondary Education.
    Keywords: Geography ; Chemistry ; Literature ; Geology ; Light ; Optics ; Biology ; History ; Physics
    Language: Portuguese
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  • 18
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    The Making of Modern Psychiatry (2021)
    Logos Verlag Berlin | Logos Verlag Berlin
    Details
    Publication Date: 2024-04-05
    Description: The field of psychiatry changed dramatically in the latter half of the nineteenth century, largely by embracing science. The transformation was most evident in Germany, where many psychiatrists began to work concurrently in the clinic and the laboratory. Some researchers sought to discover brain correlates of mental illness, while others looked to experimental psychology for insights into mental dynamics. Featured here, are the lives and works of Emil Kraepelin - often considered the founder of modern scientific psychiatry, his teacher Bernhard Gudden, and his anatomist colleague Franz Nissl. The book describes scientific findings together with the methods used; it explains why diagnoses were then (and are still now) so difficult to make; it also explores mind-brain controversies. The Making of Modern Psychiatry will inform and delight mental health professionals as well as all persons curious about the origins of modern psychiatry.
    Keywords: Science ; Life Sciences ; Biology ; Psychology ; Technology & Engineering ; Agriculture ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences ; thema EDItEUR::J Society and Social Sciences::JM Psychology ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TV Agriculture and farming
    Language: English
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  • 19
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    Biohacking, Bodies and Do-It-Yourself (2021)
    transcript Verlag | transcript Verlag
    Details
    Publication Date: 2024-03-27
    Description: From self-help books and nootropics, to self-tracking and home health tests, to the tinkering with technology and biological particles - biohacking brings biology, medicine, and the material foundation of life into the sphere of »do-it-yourself«. This trend has the potential to fundamentally change people's relationship with their bodies and biology but it also creates new cultural narratives of responsibility, authority, and differentiation. Covering a broad range of examples, this book explores practices and representations of biohacking in popular culture, discussing their ambiguous position between empowerment and requirement, promise and prescription.
    Keywords: Culture ; Representation ; Biology ; Medicine ; Biocultures ; Biohacking ; Biotechnology ; Cultural Narratives ; DIY ; America ; Body ; Biopolitics ; American Studies ; Life Sciences ; Cultural Studies ; thema EDItEUR::D Biography, Literature and Literary studies::DS Literature: history and criticism::DSB Literary studies: general ; thema EDItEUR::J Society and Social Sciences::JP Politics and government::JPA Political science and theory ; thema EDItEUR::M Medicine and Nursing::MB Medicine: general issues
    Language: English
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  • 20
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    Biologie, abondance et cartographie de deux espèces de bivalves : l’huitre perlière 〈Pinctada radiata〉 et la coque glauque 〈Cerastoderma glaucum〉 dans le golfe de Gabes (2014)
    Details
    Publication Date: 2021-05-19
    Description: The pearl oyster Pinctada radiata and the cockle Cerastoderma glaucum are among the most abundant bivalve molluscs in southern Tunisian waters. These species are not currently subject to any investigation despite their important economic value in the world. For this reason, their biological parameters, their spatial distribution and their stock assessment were undertaken in the Gulf of Gabes. The reproductive cycle was studied in relation to variations of the environment parameters. The specimens were collected monthly during one year (2007) in sites of El Kraten and El Jorf (Kerkennah Islands) for the first species and sites of Sidi Mansour and El Hicha (North of Sfax and Gabes) for the second. An intraspecific polymorphism biometric trait for P. radiata and C. glaucum was performed using statistical comparison methods and multivariate analysis methods. Results of analyzes showed heterogeneity between populations. For Pinctada radiata, the sex ratio unbalanced, although males dominated among smaller individuals and females were predominant in larger size-classes. Evidence of protrandric hermaphroditism was observed with males maturing earlier than females. Seasonal changes in macroand microscopic properties of the gonads of both sexes showed that this species displayed a clearly defined annual reproductive cycle with a major peak in summer and a minor peak in autumn. The onset of reproduction appears to be triggered by the rising seawater temperature during spring and summer. P. radiata exhibited a short resting phase that occurred simultaneously in both sexes from the end of December until early February. For Cerastoderma glaucum, the overall samples presented a balanced sex ratio, with males dominating among smaller individuals and females predominating in larger size classes. The seasonal changes assessed through macro- and microscopic properties in the gonads of both sexes indicated a clearly defined annual reproductive cycle. Reproductive activity of C. glaucum was greatest from spring to late autumn, with two reproductive peaks (May and November). Gametogenic activity in both sexes was apparently triggered by the rising seawater temperature during spring and summer. These results support previous findings of latitudinal changes in the reproductive behaviour of C. glaucum. Due to the extensive period of gonadal activity, C. glaucum exhibited a short resting phase that occurred simultaneously in both sexes throughout January and February. In terms of stock assessment and spatial distribution of P. radiata, results showed a scattered distribution pattern of the species according to location and depth ranging between 0 and 145 ind.m-². P. radiata was encountered from the intertidal zone to 40 m depth, with a highest population densities recorded at depth range of 2-20 m. The total stock was estimated to be 27584.9 ± 11504.5 million individuals. Oyster distribution seems influenced by the substrate type. This high population of pearl oysters was associated with large cover of seagrass Posidonia oceanica which provides an excellent substratum for attachment. The littoral zone seems not to be the preferred habitat for the proliferation of this immigrant species. Oysters’ size increased steadily with depth, ranging from a mean of 37.98 ± 0.40 mm SH at 0-1 m to 60.98 ± 0.68 mm SH at 20-100 m depth range. Size structure analysis showed that deep water population was dominated by large individuals reaching 96 mm SH. In terms of geographical occupation and stock assessment of C. glaucum, results showed a scattered distribution pattern of the species according to location. The consequence was a remarkable biomass which represented 4736 tons of total fresh weight and high abundance levels reaching over 1982 million individuals estimated in the area of 20122 hectares. In conclusion, this study is the first report of an extraordinary abundance of Pinctada radiata and Cerastoderma glaucum in southern Tunisian waters. It gives more information about their stocks in the colonization area. The data may help to determine future quantitative changes indicating trends in the study area that are exposed to various factors of environmental conditions and human activities.
    Description: Submitted
    Description: ABONDANCE
    Description: BILOGIE
    Description: Pinctada radiata
    Description: Cerastoderma glaucum
    Description: Huitre perlière
    Keywords: Abundance ; Biology ; Shellfish
    Repository Name: AquaDocs
    Type: Theses and Dissertations , Phd thesis
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  • 21
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    Caracterização e distribuição do fitoplâncton na zona norte da costa angolana em Agosto de 2002. (2014)
    Universidade Agostino Neto, Luanda
    Details
    Publication Date: 2021-05-19
    Description: Instittuto Nacional de Investigaçao Pesqueira, INIP, luanda , Angola
    Description: Bachelors
    Description: Trabaho de fin cdoursado para obtençâo do grau de licenciatura em Biologica
    Description: Published
    Description: biologia marinha, fitoplâncton, limnologia, algas
    Description: marine biology, phytoplankton, algae,
    Keywords: Phytoplankton ; Nannoplankton ; Biology ; Limnology ; Algae
    Repository Name: AquaDocs
    Type: Theses and Dissertations , Bachelor thesis
    Format: 56
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  • 22
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    Femtosecond switching of magnetism via strongly correlated spin-charge quantum excitations (2013)
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2013-04-05
    Description: The technological demand to push the gigahertz (10(9) hertz) switching speed limit of today's magnetic memory and logic devices into the terahertz (10(12) hertz) regime underlies the entire field of spin-electronics and integrated multi-functional devices. This challenge is met by all-optical magnetic switching based on coherent spin manipulation. By analogy to femtosecond chemistry and photosynthetic dynamics--in which photoproducts of chemical and biochemical reactions can be influenced by creating suitable superpositions of molecular states--femtosecond-laser-excited coherence between electronic states can switch magnetic order by 'suddenly' breaking the delicate balance between competing phases of correlated materials: for example, manganites exhibiting colossal magneto-resistance suitable for applications. Here we show femtosecond (10(-15) seconds) photo-induced switching from antiferromagnetic to ferromagnetic ordering in Pr0.7Ca0.3MnO3, by observing the establishment (within about 120 femtoseconds) of a huge temperature-dependent magnetization with photo-excitation threshold behaviour absent in the optical reflectivity. The development of ferromagnetic correlations during the femtosecond laser pulse reveals an initial quantum coherent regime of magnetism, distinguished from the picosecond (10(-12) seconds) lattice-heating regime characterized by phase separation without threshold behaviour. Our simulations reproduce the nonlinear femtosecond spin generation and underpin fast quantum spin-flip fluctuations correlated with coherent superpositions of electronic states to initiate local ferromagnetic correlations. These results merge two fields, femtosecond magnetism in metals and band insulators, and non-equilibrium phase transitions of strongly correlated electrons, in which local interactions exceeding the kinetic energy produce a complex balance of competing orders.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Li, Tianqi -- Patz, Aaron -- Mouchliadis, Leonidas -- Yan, Jiaqiang -- Lograsso, Thomas A -- Perakis, Ilias E -- Wang, Jigang -- England -- Nature. 2013 Apr 4;496(7443):69-73. doi: 10.1038/nature11934.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23552945" target="_blank"〉PubMed〈/a〉
    Keywords: Biology ; Chemistry ; Circular Dichroism ; Electronics ; Iron/chemistry ; *Magnetic Phenomena ; Magnetics ; Optics and Photonics ; Photosynthesis ; *Quantum Theory ; Temperature ; Time Factors
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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    Reality at risk (2013)
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2013-09-14
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉England -- Nature. 2013 Sep 12;501(7466):136.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24032131" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Autobiography as Topic ; Biology ; *Literature, Modern ; Physics ; *Research Personnel ; Self Concept
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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  • 24
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    The differential effects of changing management regimes on yields from two fisheries exploiting the same resources (2013)
    Details
    Publication Date: 2021-05-19
    Description: A yield per recruit model has been used to compare the effects of mesh size increment on the yields and revenues of the fisheries of Cameroon under two different cases. Case 1 assumes the commercial fishery to move from the exploitation of three age-groups to two age-groups with no interactions with the artisanal fishery, whereas Case 2 takes into account these interactions. The difference in the percentage increase of yield per recruit between case 1 and case 2 is 61% at current fishing (46% and 18% yield per recruit increment in cases 1 and 2 respectively). The usually accepted long-term yield per recruit increment with increase of age at first capture (with a single non-interacting fisheries) is, in this case, cancelled out. However, the revenues increase by 72% and 63% in cases 1 and 2 respectively. Therefore the economic approach, compared with purely biological analyses, is more convincing. In general, as fisheries always interact, a single-fishery management approach should not be the rule as it is at present; management strategies should consider interactions between different fisheries and be based on their economic performances and not, as said earlier, on purely biological considerations. This is because a biological approach to fisheries management will, at best, be modified by economic factors, or, at worst, be ignored totally in favour of economic policies.
    Description: Published
    Keywords: Biology ; Fisheries ; Biological interaction ; Sciaenidae ; Fisheries development ; Fishery management ; Yield/recruit ; Commercial fisheries ; Artisanal fishing
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
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  • 25
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    Le chinchard Ouest africain (Trachurus trecae) biologie et recommandations pour l'exploitation optimale du stock sénégalo-mauritanien de la zone économique mauritaniennes (2013)
    Details
    Publication Date: 2021-05-19
    Description: Published
    Description: Chinchard (Trachuurus trecae)
    Description: Biologie
    Keywords: Biology ; Exploitation
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
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  • 26
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    Marquage des langoustes en Mauritanie (2013)
    Details
    Publication Date: 2021-05-19
    Description: Published
    Description: langoustes
    Description: marquage
    Description: poisson
    Keywords: Lobsters ; Biology ; Ecology ; Aquatic biology
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
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  • 27
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    Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl in the summer session of 1895 (2012)
    Ginn & Co. | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1895
    Description: Publications
    Keywords: Biology ; Publications
    Repository Name: Woods Hole Open Access Server
    Language: English
    Type: Text
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    Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl in the summer session of 1893 (2012)
    Ginn & Co. | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1893
    Description: Publications
    Keywords: Biology ; Publications
    Repository Name: Woods Hole Open Access Server
    Language: English
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    Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl in the summer session of 1890 (2012)
    Ginn & Co. | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1890
    Description: Preface -- Specialization and organization, companion principles of all progress. The most important need of american biology, by C.O. Whitman -- Naturalist's occupation: 1. general survey. 2. a special problem, by C.O. Whitman -- Some problems of Annelid morphology, by E.B. Wilson -- Gastraea theory and its successors, by J.P. McMurrich -- Weismann and Maupas on the origin of death, by Edward G. Gardiner -- Evolution and heredity, by Henry Fairfield Osborn -- Relationships of the sea-spiders, by T.H. Morgon -- On caryokinesis, by S. Watase -- Ear of man: its past, present and future, by Howard Ayers -- Study of Ocean temperatures and currents, by William Libbey, Jr.
    Description: Publications
    Keywords: Biology ; Publications
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    Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl in the summer session of 1894 (2012)
    Ginn & Co. | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1894
    Description: Publications
    Keywords: Biology ; Publications
    Repository Name: Woods Hole Open Access Server
    Language: English
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  • 31
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    Biological lectures from the Marine Biological Laboratory of Woods Holl, 1899 (2012)
    Marine Biological Laboratory (Woods Hole, Mass.) | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1899
    Description: Evolution of the sporophyte in the higher plants, by Douglas Houghton Campbell -- Nature of the evidence exhibited by fossil plants, and its bearing upon our knowledge of the history of plant life, by D.P. Penhallow -- Influence of inversions of temperature, ascending and descending currents of air, upon distribution, by D.T. MacDougal -- Significance of mycorrhizas, by D.T. MacDougal -- Instinct, by Edward Thorndike -- Associative processes in animals, by Edward Thorndike -- Behavior of unicellular organisms, by Herbert S. Jennings -- Blind-fishes, by Carl H. Eigenmann -- Some governing factors usually neglected in biological investigations, by Alpheus Hyatt -- On the development of color in moths and butterflies, by Alfred Goldsborough Mayer -- Physiology of secretion, by A. Mathews -- Regeneration: old and new interpretations, by T.H. Morgan -- Nuclear division in protozoa, by Gary N. Calkins -- Significance of the spiral type of cleavage and its relation to the process of differentiation, by C.M. Child -- Aims of the quantitative study of variation, by C.B. Davenport -- On the nature of the process of fertilization, by Jacques Loeb
    Description: Publications
    Keywords: Biology ; Publications
    Repository Name: Woods Hole Open Access Server
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    Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl, 1896-1897 (2012)
    Ginn & Co. | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1896-1897
    Description: Variations and mutations of the introduced sparrow. Passer domesticus, by Hermon C. Bumpus -- Cleavage and differentiation, by E.G. Conklin -- Centrosomes of the fertilized egg of Allolobophora foetida, by Katharine Foot -- Methods of palacontological inquiry, by W.B. Scott -- Physiology of excretion, by Arnold Graf -- Some neural terms, by Burt G. Wilder -- Classification of the North American Taxaccae and Coniferae on the basis of the stem structre, by D.P. Penhallow -- Selection of plant types for the general biology ccourse, by James Ellis Humphrey -- Rate of Cell-division and the function of the centrosome, by A.D. Mead -- Coalescence experiments upon the Lepidoptera, by Henry E. Crampton, Jr. -- Some of the functions and features of a biological station, by C.O. Whitman
    Description: Publications
    Keywords: Biology ; Publications
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    Biological lectures from the Marine Biological Laboratory Wood's Holl, Mass., 1898 (2012)
    Ginn & Co. | Biodiversity Heritage Library
    Details
    Publication Date: 2023-01-12
    Description: Biological lectures given at the Marine Biological Laboratory in Woods Hole in the summer of 1898
    Description: Publications
    Keywords: Biology ; Publications
    Repository Name: Woods Hole Open Access Server
    Language: English
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  • 34
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    Winter wheat yield response to climate variability in Denmark (2011)
    In:  Journal of Agricultural Science, Volume: 149, p.33-47
    Details
    Publication Date: 2011
    Description: Verwendung eines gemischten Regressionsmodels für die Vorhersage der Kornernte unter fünf Klimaszenarien für zwei Bodentypen (sandige und lehmige Böden) und zwei Regionen in Dänemark (West Zealand und Central Jutland). KATASTER-BESCHREIBUNG: Auswirkung von Änderungen im Klima (Temperatur und Strahlung) auf die Ernteerträge von Getreide. Im Durchschnitt nehmen die Erträge unter den projizierten Klimaänderungen um 1.6-12.3% ab. Die durchschnittliche Abnahme bis 2020 beträgt 3.6% verglichen zum Jahr 1985 und 8.0% bis 2040. Die Abnahme ist für West Zealand größer als für Central Jutland und für lehmige Böden größer als für sandige Böden. KATASTER-DETAIL: Delta T (Sommer) +, dann Erträge -; Delta Sonn (Sommer, Frühling) +, dann Erträge +; Delta T (Winter) = 4,4°C, dann Erträge = max; Delta T (Winter) 〉/〈 4,4°C, dann Erträge -;
    Keywords: Dänemark ; 1992-2008, 2020, 2040 ; Ertrag ; Getreide ; Klima ; Niederschlag ; Temperatur ; Sonnenscheindauer ; Modell
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  • 35
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    Klimawandel und Apfelertrag - Einfluss von Witterung und Klima auf die Ertragsbildung an der Niederelbe (2011)
    In:  DGG-Proceedings, Vol. 1, No. 3, p. 1-5. DOI: 10.5288/dgg-pr-01-03-hh-2011
    Details
    Publication Date: 2011
    Description: Modifizierte Wasserhaushalts- und Ertragsmodell SIMWASER wurde genutzt, um auf der Grundlage von Klimaszenarien zukünftige Apfelerträge an der Niederelbe abzuschätzen. KATASTER-BESCHREIBUNG: ECHAM5/ OM IPCC, Szenariolauf 1, WETTREG Klimaszenarien A1B und B1, Eingang in das Regressionsmodell fanden das Vorerntejahr (*) die Sonnenscheindauer von April-Juni [Sd(04-06)*], Minimumtemperatur im November [Tn(11)*], Sonnenscheindauern im März/April [Sd(0304)] und im Mai/Juni [Sd(0506)] und die Niederschlagshöhe im Juli des Erntejahres [P07] Modellrechnungen ergeben bis zum Ende des 21.Jahrhunderts Veränderungen der phänologischen Phasen sowie der Apfelerträge.Insbesondere die signifikante Verkürzung der Periode BBCH[61-87] (p〈0.01) um 28(Szenario A1B) bzw. 19 Tage (Szenario B1) bis zum Ende des 21. Jahrhunderts ist vermutlich der maßgebliche Faktor für die signifikante Abnahme der Erträge um ca. 7 % an der Niederelbe bei sonst gleichbleibenden Rahmenbedingungen. KATASTER-DETAIL: Anomalie (yi in Prozent) der beobachteten Erträge (xoy) zum linearen Ertragstrend (xlyt) bestimmt: yi = (xoy)i / (xlyt)i Ertagsabweichung delta-y = 0.805679 + 0.00103065 Sd(04-06)* - 0.0468646 Tn11* - 0.00110369 Sd(0304) + 0.00031381 Sd(0506) - 0.00153245 P07
    Keywords: Niedersachsen ; 1973-2006 und Szenarium von 2001-2100 ; Apfel ; Ertrag ; Niederschlag ; Vegetationsperiode ; Sonnenscheindauer
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  • 36
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    Bewertung des Risikoausgleichspotentials von Wetterderivaten im Agribusiness am Beispiel der Nordzucker AG (2011)
    In:  Masterarbeit, Kiel
    Details
    Publication Date: 2011
    Description: Ermittlung der Wettervariablen mit dem höchsten Risikoausgleichspotential an 13 untersuchten Standorten KATASTER-BESCHREIBUNG: Korrelation von Temperatur, Niederschlag und Sonnenscheinstungen und Zuckerertrag in Norddeutschland KATASTER-DETAIL: Korrelationskoeffizienten von 0,756 bei der Temperatur, einen Wert von -0,845 beim Niederschlag und einen Korrelationskoeffizienten bei den Sonnenstunden von 0,846
    Keywords: Norddeutschland ; 2001 - 2010 ; Zuckerrüben ; Ertrag ; Niederschlag ; Temperatur ; Sonnenscheindauer
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    Contribuciones científicas del Instituto de Investigaciones Marinas de Punta de Betín "INVEMAR", publicadas entre 1966 y 1982 (2011)
    Santa Marta (Colombia), INVEMAR
    Details
    Publication Date: 2021-05-19
    Description: Se incluyen en el análisis 271 trabajos publicados en diversas revistas científicas y cuyo material básico de estudio fue observado, colectado y analizado en el Caribe colombiano, pero fundamentalmente en el área de influencia directa del INVEMAR. Las contribuciones han sido publicadas en alemán (111), español (109) e inglés (51). Dichos trabajos incluyen investigaciones de carácter descriptivo (175) y analítico (96) e involucran el ambiente terrestre (91) y el acuático (180). Las regiones incluidas en loa estudios son: Parque Tayrona (84), Santa Marta (59), Ciénaga Grande (51) y otras áreas (77); y en cuanto a las ramas de la ciencias: la Biología (212), la Geología (9) y otras áreas (50).
    Description: Two hundred and seventy one works published in different scientific journals are included and whose basic study material was observed, collected and analized in the Colombian Caribbean, but basically in INVEMAR direct influence área. The contributions have been published in Germán (111), Spanish (109)and English (51). These works include research of descriptive character (175) and analitic (96), and involve land (91) and aquatic (180) environments. The regions included in the studies are the following: Tayrona Park (84), Santa Marta (59), Ciénaga Grande (51), and other arcas (77); and concerning the scientific branches: Biology (212), Geology (9) and other arcas (50).
    Description: Published
    Description: Bibliography,
    Keywords: Estuaries ; Geology ; Coastal lagoons ; Biology ; Coastal lagoons ; Estuaries ; Biology ; Geology
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    Observations on the biology of the redlip Blenny, Ophioblennius atlanticus (Pisces: Blenniidae) on the Colombian Coast of the Caribbean (2011)
    Santa Marta (Colombia), INVEMAR
    Details
    Publication Date: 2021-05-19
    Description: During a 3 week study, a total of 55 individuals of the redlip blenny (Ophioblennius atlanticus) were observed for at least two 15-minute periods, and several for ten of such periods. The sizes of their territories were estimated, the color pattern of each specimen an intra and interspecific interactions were recorded. The mean territory size of the redlip blenny in the study area appeared to be greater than that of these blennies studied in Curacao and Barbados by NURSALL (1977), the difference reflecting perhaps different methods of identifying the territories or a lower density of O. atlanticus in the Santa Marta área. Territories did not appear to be as consistently defended at the study area as at Barbados/Curacao and our impression ¡s that individuals holding large territories are less likely to defend their borders. It seems possible that light colored individuals are protected by their coloration from attack by dark colored territory owners. In territorial defense the redlip blennies grabbed each other tighthy by the mouth and struggled in this position repeatedly for about 15 seconds. Interspecific antagonism was common in the present study, the redlip blennics defended their territory frequently against Eupomacentrus dorsopunicans or E. partitus.
    Description: Durante un estudio de tres semanas, un total de 5 i individuos del bií'nido Ojih'toblcnnius atlnniicur. fueron observados por lo menos durante dos períodos de 1 í minutos para cada individuo y en algunos casos hasta por 10 de estos periodos. Se estimó el área de sus respectivos territorios y se tomó notí de los patrones de coloración de cada espécimen y de las relaciones intra e interespecificas de ellos. El tamaño promedio del territorio de estos blénidos resultó ser mayor que el de los respectivos territorios estudiados por NURSALL (1977) en Curacao y Barbados. Esta diferencia posiblemente se debe a un método diferente de definir los territorios o refleja una densidad menor de la población de O. aílanticus en Santa Marta, Los territorios del área fueron defendidos con menor intensidad a como lo fueron los de Barbados/ Curacao y es nuestra impresión que individuos ocupando un territorio extenso tienden a defender sus límites en menor grado. El color claro de algunos individuos probablemente los protege de agresiones por parte de individuos de color oscuro. En el acto de defensa territorial intraespecífica, los blénidos se agarran por sus bocas y se sacuden mutuamente durante aproximadamente 15 segundos , pudiéndose repetir esti varias veces. Con frecuencia se observarondefensas de los territorios dirigidas hacia los peces doncella Eupomacentrus dorsopunicnas y E. partitus.
    Description: Published
    Keywords: Fisheries ; Biology ; Fisheries ; Biology
    Repository Name: AquaDocs
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  • 39
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    Sistemática, biología y ecología del Titi Sicydium antillarum Grant (Pisces: Gobiidae) en la región de Santa Marta, Colombia (2011)
    INVEMAR, Santa Marta (Colombia)
    Details
    Publication Date: 2021-05-19
    Description: Sícydium antillarum Grant es un gobiido abundante en las corrientes que bajan de la SierraNevada de Santa Marta (Colombia) al mar. Se estudió la población de la Quebrada Valencia y las postlarvas en las bocas de los ríos Manzanares y Gaira, entre febrero de 1987 y enero de 1988. Se presentan datos morfológicos, merísticos y morfométricos de la especie; la población desovó de mayo a diciembre, con picos máximos en junio y octubre. La proporción hembras: machos fue casi 1:1 de enero a marzo; de abril a diciembre los machos se apoderan de un territorio y se dificulta su captura, principalmente en septiembre y octubre (proporción 9:1). La fecundidad máxima fue de 91067 huevos en una hembra de 109 mm; el 25% de los ejemplares alcanzó la madurez entre 60.0 y 64.9 mm. La relación talla (mm) - peso (gr) fue: Peso = 1.039x10'6 xlongitud total 35232 . El factor de condición sufre un descenso en noviembre, después del mayor pico de desove de la estación lluviosa. Los contenidos estomacales estaban integrados por algas y bacterias; la especie es diurna, encontrándose el 100% de individuos con el estómago lleno a las 15:00 horas. Las postlarvas fueron detectadas cada mes entre agosto y diciembre, al fin del cuarto menguante; adultos y postlarvas son resistentes a condiciones de laboratorio.
    Description: Sicydium antillarum Grant is an abundant gobiidfish ¡n the streams which runfrom the Sierra Nevada de Santa Marta (Colombia) tothe sea. The population living in the Quebrada Valencia was studiedfrom February 1987 to January 1988; postlarvae were observed and collected at the mouths of the Manzanares and Gaira rivers. Morphological, meristic and morphometric data of the species are presented; the population spawned between May and December, with peaks in June and October. Sex ratios between January and March were around 1:1; males defend a territory from April to December and are more difficult to capture (mainly in September and October, when the ratios are about ninefemales per male). The highest numberof eggs (91,067) was found in a female 109 mm in íength. Twenty-five per cent of the specimens reached maturity between 60.0 and 64.9 mm. The equation relating íength (mm) and weigth (gr) is: Weígth = 1.0309xtO*6 xtotal íength 35232 . Condition factor reached a low valué in November.that is after the highest spawning peak of the rainy season. The stomach contents studied were composed of algae and bacteria; all the specimens collected at 15:00 had a full stomach, which indicates that the species is diurnal. Postlarvae were detected monthly from August top December, always related to the waning moon. Adults and postlarvae are very hardy and live well in laboratory conditions.
    Description: Published
    Keywords: Ecology ; Geographical distribution ; Reproductive behaviour ; Feeding behaviour ; Ichthyology ; Biology ; Ecology ; Ichthyology ; Geographical distribution ; Reproductive behaviour ; Feeding behaviour ; Biology ; Morphometry ; Stomach content
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  • 40
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    Peces de las Islas del Rosario y de San Bernardo (Colombia) II. Tres nuevos registros para el Caribe Sur y 16 mas para la Costa Norte continental colombiana (2011)
    Santa Marta (Colombia), INVEMAR
    Details
    Publication Date: 2021-05-19
    Description: Se describen 19 especies de peces colectadas en los archipiélagos coralinos de las islas del Rosario y de San Bernardo, las cuales son nuevos registros para el Caribe continental colombiano. Tres de esas especies (Ichthyapus ophioneus, Calamopteryx goslinei y Apogon leptocaulus) no habían sido colectadas antes en el Caribe sur, por lo que estos récords son nuevos para este sector del Mar de las Antillas. Se incluye información sobre aspectos biológicos y ecológicos de las especies.
    Description: 19 species of fishes coliected in the coralline archipelagos of Islas de) Rosario and San Bernardo, which are reponed for the first time for the Colombian continental Car¡bbean, are described. Three of those species (Ichtyapus ophioncus, Calamopteryx goslmei and Apogon leptocaulus) had not been collected before in the southern Caribbean, being therefore new records for this section of the Sea. Biological and ecological information about the 19 species is given as well.
    Description: Published
    Keywords: Fish ; Ecology ; Biology ; Fish ; New records ; Biology ; Ecology
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  • 41
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    Recent changes in the climatic yield potential of various crops in Europe (2010)
    In:  Agricultural Systems, Volume: 103, Issue: 9, p.683-694
    Details
    Publication Date: 2010
    Description: Mit Hilfe des Crop Growth Monitoring Systems wurden Veränderungen im simulierten potentiellen Ertrag von Kulturpflanzen und in der Biomasseproduktion beobachtet, die durch die Temperaturänderungen und Globalstrahlungsmuster hervorgerufen werden. KATASTER-BESCHREIBUNG: Die Veränderungen im potentiellen Ertrag sind geographisch unterschiedlich. In Italien und Südmitteleuropa sinkt bei mehr als drei Arten der potentielle Ertrag signifikant. In nordeuropäischen Regionen wie Großbritannien steigt das Ertragspotential mehrerer Kulturpflanzen. KATASTER-DETAIL: -
    Keywords: Europa ; 1967-2005 ; Ertrag ; Temperatur ; Globalstrahlung
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  • 42
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    Modelling climate impacts on crop yields in Belgium (2010)
    In:  Climate Research, Volume 44, Issue: 1, p.55-68
    Details
    Publication Date: 2010
    Description: Entwicklung eines neuen regionalen Ernte-Models (REGCROP) zur Abschätzung von Auswirkungen des Klimas auf die regionale Ackerfruchtproduktion. Es wurden Durchläufe für 3 verschiedene Klimaszenarien und 3 typische belgische Böden (Ton, Lehm, lehmiger Sand) durchgeführt. Die Klimaauswirkungen wurden mit historischen Wetterauswirkungen verglichen. KATASTER-BESCHREIBUNG: Einfluss des Klimas (Temperatur, Niederschlag, Luftfeuchte) auf den Ertrag von Kulturpflanzen KATASTER-DETAIL: Delta T +, dann Entwicklung der Kulturpflanze + und Vegetationszeit -; Delta T + (Hitzestress) und Delta Nied - (Trockenheit), dann Ertrag (Zuckerrüben) - um 12-27% und Ertrag (Kartoffeln) - um 23-44%; Delta Nied + (Vernässung), dann Ertrag (Wintergetreide) - um 5-12%; Delta T + und günstige Dampfdruckdefizite, dann Ertrag + um 6-7%;
    Keywords: Belgien ; 1960-2008 ; Zuckerrüben ; Kartoffeln ; Ertrag ; Getreide ; Klima ; Temperatur ; Trockenheit ; Modell
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  • 43
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    Newsmaker interview. Down-to-earth science fiction. Interview by Elizabeth Pennisi (2010)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2010-02-13
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wilson, Edward O -- New York, N.Y. -- Science. 2010 Feb 12;327(5967):775. doi: 10.1126/science.327.5967.775.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20150461" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Ants ; Biology ; *Ecosystem ; *Literature, Modern
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 44
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    Latin America. Chile's earthquake may set back research for years (2010)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2010-03-13
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kaiser, Jocelyn -- Regalado, Antonio -- New York, N.Y. -- Science. 2010 Mar 12;327(5971):1308-9. doi: 10.1126/science.327.5971.1308.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20223953" target="_blank"〉PubMed〈/a〉
    Keywords: Biology ; Biotechnology ; Chile ; *Disasters ; *Earthquakes ; Laboratories ; *Research ; Universities
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 45
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    Bases biológicas de Ulva fasciata Delile, (Chlorophyta) para su posible explotación al Oeste de La Habana, Cuba. (2010)
    Universidad de la Habana
    Details
    Publication Date: 2021-05-19
    Description: El objetivo de esta tesis es caracterizar las poblaciones naturales de Ulva fasciata en el sector comprendido entre los ríos Quibú y Jaimanitas al oeste de La Habana, típico de costas de emersión del Caribe Occidental, con vistas a su posible explotación. El estudio se realizó entre marzo de 1996 y enero del 2001. Los resultados más importantes permitieron comprobar que la especie U. fasciata no se distribuye de forma similar en todo este sector, en la cobertura algal intervienen de manera decisiva, el tipo de sustrato y la disponibilidad de nutrientes en el medio. Los compuestos del nitrógeno y el fósforo en el agua de mar y las diferencias en la amplitud de variación de los mismos, justifican las diferencias en la morfometría, la biomasa en pie y el estado nutricional (C, N, P) de U. fasciata y evidencia el carácter oportunista de la especie. Estas condiciones ambientales son poco variables en el tiempo, este hecho garantiza la presencia de su población, cada año, en este sector. El desarrollo de la población de U. fasciata, se favorece cuando la temperatura superficial del mar oscila entre 24ºC y 26,5ºC, los niveles de radiación global fluctúan entre 13,4 mj.m-2 y 24 mj.m-2 y acontecen precipitaciones moderadas que no exceden los 190 mm de acumulado mensual. La biomasa en pie decrece considerablemente en el verano, coincidiendo con las altas temperaturas superficiales del mar (29ºC-30ºC) y las precipitaciones intensas (〉190 mm acumulado mensual). Aunque la biomasa por unidad de área fluctúa en el tiempo, su ciclo anual tiene un patrón muy similar en todo el sector. U. fasciata tiene un contenido alto de clorofila a y b, carotenoides, proteína, carbohidratos, fibra y cenizas, así como de otros macronutrientes (Ca, Mg y K) y micronutrientes (Fe, Zn, Cr y Mn). La concentración de estos componentes manifiesta variaciones espaciales y temporales de acuerdo a los diferentes niveles de nutrifización del medio. Las concentraciones máximas de componentes en los talos coinciden con las mayores acumulaciones de biomasa en pie y acontecen en las zonas cercanas a los ríos. Esta especie posee bajo contenido de lípidos. Existen niveles altos de bacterias coliformes totales y fecales en U. fasciata, por lo que su calidad higiénico-sanitaria no siempre es buena y debe ser tratada si se desea explotar este recurso para diferentes fines.
    Description: Ulva fasciata, explotación
    Keywords: Algae ; Biology ; Algae ; Biology
    Repository Name: AquaDocs
    Type: Theses and Dissertations
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  • 46
    Electronic Resource
    Electronic Resource
    Photoelektronenspektren und Moleküleigenschaften, XXVI. Die Delokalisation von Schwefel-Elektronenpaaren in Alkylsulfiden und -disulfiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 68-77 
    Details
    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 Molecular Properties, XXVI. The Delocalisation of Sulfur Electron Pairs in Sulfides and DisulfidesThe photoelectron (PE) spectra of sulfides R—S—R (R=H, CH3, C2H5, n- und i-C3H7, n- and tert-C4H9) and disulfides R—S—S—R (R=H, CH3, C2H5, n- and i-C3H7, tert-C4H9, —[CH2]4—) are comparatively discussed. For sulfides the first ionization energy, which decreases as expected with increasing degree of alkylation, can also be obtained from the charge transfer excitation energies of their σ-complexes with tetracyanoethylene (TCNE). Disulfides show a splitting of the first PE-band in a clear dependence on the dihedral angle of the sulfur electron pairs. All observations can be rationalised within MO models as interactions of the sulfur electron pairs with the σ-skeleton and/or with each other.
    Notes: Die Photoelektronen(PE)-Spektren von Sulfiden R—S—R (R=H, CH3, C2H5, n- und i-C3H7, n- und tert-C4H9) und Disulfiden R—S—S—R (R=H, CH3, C2H5, n- und i-C3H7, tert-C4H9, —[CH2]4—) werden vergleichend diskutiert. Bei den Sulfiden R—S—R kann die mit steigendem Alkylierungsgrad erwartungsgemäß abnehmende erste Ionisierungsenergie auch aus den Charge-transfer-Anregungsenergien ihrer σ-Komplexe mit Tetracyanäthylen (TCNE) abgelesen werden. Bei Disulfiden R—S—S—S—R wird eine Aufspaltung der ersten PE-Bande in deutlicher Abhängigkeit vom Diederwinkel zwischen den Schwefel-Elektronen-paaren beobachtet. Die Befunde lassen sich mit MO-Modellen als Wechselwirkungen der Schwefel-Elektronenpaare mit dem σ-Gerüst und/oder untereinander verstehen.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070109
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  • 47
    Electronic Resource
    Electronic Resource
    Ylid-Komplexe von Nickel-alkylen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 93-101 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nickelalkyl Ylid ComplexesFrom reactions of [(CH3)3P]3 Ni(CH3)2 and [(CH3)3P]2Ni(CH3)Cl with the ylid (CH3)3PCH2, molecular (1) an ionic complexes (2) are obtained, containing three covalent Ni—C-σ-bonds of square planar nickel atoms. These bonds are strongly stabilized by the proximity of the ylid onium center. Excess ylid converts 2 into a binuclear complex 3, where the metal atoms are bridged by dimethylphosphonium-bismethylid units, with formation of [(CH3)4P]Cl as a byproduct. An isoelectronic dimethylphosphinate complex, 4, containing a similar eight-membered ring structure, has also been prepared.
    Notes: Durch die Reaktion von Dimethyltris(trimethylphosphin)nickel und Methylbis(trimethyl-phosphin)nickel-chlorid mit Trimethylmethylenphosphoran werden molekulare (1) bzw. ionische (2) Ylid-Komplexe erhalten, in denen das quadratisch-planar konfigurierte Nickel-atom jeweils drei kovalente Ni—C-σ-Bindungen ausbildet. Diese Bindungen werden durch das Onium-Zentrum der Ylide erheblich stabilisiert. 2 liefert mit überschüssigem Ylid unter Abspaltung von [(CH3)4P]Cl einen zweikernigen Komplex 3, dessen Metallatome durch Dimethylphosphonium-bis-methylid-Brücken verbunden sind. Hierzu existiert ein isoelektronischer Dimethylphosphinat-Komplex 4, der ebenfalls Achtringstruktur besitzt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070111
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  • 48
    Electronic Resource
    Electronic Resource
    Reaktionen carbonyl-stabilisierter Sulfonium-ylide des 1,3-Dithiolans mit Acylierungsmitteln und aktivierten Acetylenen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 123-127 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of carbonyl-stabilized Sulfonium-ylides of 1,3-Dithiolane with Acylating Reagents and Activated AcetylenesIn aqueous sodium hydroxide monophenacyl-1,3-dithiolanium bromides 3 form carbonylstabilized 1,3-dithiolanium-1-phenacylides 4. These yield with acylation reagents and activated acetylenes new resonance-stabilized sulfonium-ylides 6, 8, 10.
    Notes: Monophenacyl-1,3-dithiolanium-bromide 3 bilden in wäßriger Natronaluge carbonyl-stabilisierte 1,3-Dithiolanium-1-phenacylide 4. Diese reagieren mit Acylierungsmitteln und aktivierten Acetylenen zu neuen mesomeriestabilisierten Sulfonium-yliden 6, 8, 10.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070115
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  • 49
    Electronic Resource
    Electronic Resource
    Über Aminosäuren und Peptide, IX. Über Pyruvoylaminosäuren (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 145-151 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, IX. On Pyruvoyl Amino AcidsAmino acid derivatives were tranformed to Pyruvoyl amino acid derivatives by use of pyruvoyl chlorid, p-nitrophenyl pyruvate, hydroxymaleic anhydride and the DCC-procedure. The application range of the different acylations is discussed. A convenient method for the preparation of pyruvoyl chloride is given.
    Notes: Aminosäurederivate werden mit Brenztraubensäurechlorid, Brenztraubensäure-p-nitrophenylester, Hydroxymaleinsäureanhydrid und mit Hilfe des DCC-Verfahrens zu Pyruvoylaminosäurederivaten umgesetzt. Die Anwendungsbreite der verschiedenen Acylierungen wird verglichen. Ein Weg zur praktischen Herstellung von Brenztraubensäurechlorid wird ausgearbeitet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070118
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  • 50
    Electronic Resource
    Electronic Resource
    Kristall- und Molekülstruktur von Hexakis(phenylthio)äthan (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 253-262 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of Hexakis(phenylthio)ethaneThe structure of hexakis(phenylthio)ethane has been determined by single crystal X-ray diffraction. The phase determination was carried out by means of the Symbolic Addition Method. The structure has been refined with 1780 observed reflections to an R-value of 10.9%. The pseudo bodycentered unit cell contains two molecules, which are situated at the center at 0, 0, 0 and 1/2, 1/2, 1/2, respectively. The bodycentering is almost perfect for the six sulfur atoms, but does not involve the central ethane bonding, which implies that the sulfur atoms, that are connected by the centering, are bonded to different carbon atoms. The six sulfur atoms are staggered around the ethane C—C bond. The S—C—S angles of 113° are larger than the ideal tetrahedrane angles by the same amount by which the S—C—C angles of 105° are smaller. The ethane C—C distances are 1.59 and 1.56 Å respectively.
    Notes: Die Struktur des Hexakis(phenylthio)äthans wurde mit Röntgenmethoden bestimmt. Die Phasenbestimmung wurde mit der symbolischen Additionsmethode durchgeführt. Die Struktur wurde unter Benutzung von 1780 beobachteten Reflexen bis auf einen R-Wert von 10.9% verfeinert. Die pseudoinnenzentrierte Elementarzelle enthält zwei Moleküle, die um die Symmetriezentren in 0, 0, 0 bzw. 1/2, 1/2, 1/2 gelagert sind. Die Innenzentrierung ist nahezu genau für die sechs Schwefelatome, aber gilt nicht für die zentrale Äthanbindung, was zur Folge hat, daß die durch Zentrierung verbundenen Schwefelatome an verschiedene Kohlenstoffatome gebunden sind. Die sechs Schwefelatome sind gestaffelt um die Äthan-C—C-Bindung angeordnet. Die S—C—S-Winkel sind mit 113° etwas größer, die S—C—C-Winkel mit 105° um denselben Betrag kleiner als der Tetraederwinkel. Die Äthan-C—C-Abstände betragen 1.59 bzw. 1.56 Å.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070131
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  • 51
    Electronic Resource
    Electronic Resource
    Benzothiazol-N-oxide, II. Über eine neue Synthese substituierter 2-Benzothiazolone (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 305-316 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Benzothiazole N-Oxides, II. New Synthesis of Substituted 2-BenzothiazolonesIn the presence of phosphoryl chloride, 2-carbamoylbenzothiazole N-oxides undergo a new intramolecular redox reaction to give 2-benzothiazolones. In two cases investigated, also 2-ethoxycarbonylbenzothiazole N-oxides undergo this rearrangement. The spectroscopic data are discussed.
    Notes: 2-Carbamoylbenzothiazol-N-oxide gehen in Gegenwart von Phosphoroxychlorid eine neuartige intramolekulare Redoxreaktion unter Bildung von 2-Benzothiazolonen ein. In zwei untersuchten Fällen unterliegen unterliegen auch 2-Äthoxycarbonylbenzothiazol-N-oxide dieser Umlagerung. Spektroskopische Daten werden diskutiert.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070136
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  • 52
    Electronic Resource
    Electronic Resource
    Aromatische Sulfenylchloride, IX. Herstellung, Oxidation und spektroskopische Untersuchung von 1-substituierten (5-Tetrazolyl)aryldisulfiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 299-304 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aromatic Sulfenyl Chlorides, IX. Preparation, Oxidation, and Spectroscopic Investigation of 1-Substituted 5-Tetrazolyl Aryl Disulfides1-Substituted 5-tetrazolyl mesityl disulfides were synthesized which on oxidation with hydrogen peroxide gave disulfide S2, S2-dioxides (thiolsulfonates). The structure of these as well as that of the 1-substituted 5-tetrazolyl p-tolyl disulfide S2, S2-dioxides synthesized earlier was elucidated by means of their i. r. and n. m. r. spectra. The supposed structures have been established by synthesis.
    Notes: Es wurden 1-substituierte (5-Tetrazolyl)mesityldisulfide hergestellt, welche zu Disulfid-S2, S2-dioxiden (Thiosulfonate) oxidiert wurden. Deren Struktur und die der früher hergestellten 1-substituierten (5-Tetrazolyl)p-tolyldisulfid-S2, S2-dioxide wurde anhand ihrer IR- und NMR-Spektren wahrscheinlich gemacht. Die angenommenen Strukturen wurden durch Synthese bewiesen.
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    Lithio-1,3,5-trithiane Erzeugung, Umsetzung mit Elektrophilen und Verwendung als nucleophile Acylierungsmittel (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 367-379 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Lithio-1,3,5-trithianes Generation in Solution, Reactions with Electrophiles, and Use in Nucleophilic Acylation1,3,5-Trithiane and 2-mono- as well as 2,4,6-trisubstituted trithianes are shown to be metallated by n-butyllithium in THF. Reaction of the lithio derivatives thus obtained with electrophiles leads to more highly substituted trithianes which in some cases can be isolated in a pure form. The n.m.r. spectra of the products at room temperature are described. Mercury(II)-assisted solvolysis of alkyltrithianes „liberates“ the most highly substituted carbon with formation of carbonyl compounds or their O-acetals. This completes a sequence of reactions which suggests use of lithiotrithianes as reagents for nucleophilic acylation. Advantages and disadvantages of this procedure compared to the dithiane method are discussed.
    Notes: 1,3,5-Trithian selbst sowie 2-mono- und 2,4,6- trisubstituierte Trithiane lassen sich mit n-Butyllithium in Tetrahydrofuran metallieren. Umsetzung der Lithiumderivate mit Elektrophilen führt zu höher substituierten Trithianen, die teilweise in reiner Form isoliert werden können. Die NMR-Spektren der erhaltenen Produkte bei Raumtemperatur werden beschrieben. Quecksilber(II)-assistierte Solvolyse von alkylierten Trithianen führt zu Carbonyl-verbindungen oder deren O-Acetalen unter „Herauslösung“ des höchstsubstituierten C-Atoms, was die Verwendung von Lithiotrithianen als nucleophile Acylierungsmittel ermöglicht. Vor- und Nachteile gegenüber der Dithian-Methode werden diskutiert.
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    Über die Abhängigkeit der Bindungslängen in einigen N,O-Dibenzoylhydroxylaminen von der Verdrillung der Carboxyl- und Hydroxamsäuregruppen gegen die Benzolkerne Die Kristallstrukturen von N,O-Dibenzoyl-(C14H11NO3), N,O-Bis(2- chlorbenzoyl)-(C14H9Cl2NO3), N-Benzoyl-O-p-toluoyl- (C15H13NO3) und N-Benzoyl-O-o-toluoylhydroxylamin (C15H13NO3) (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 398-413 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Dependence of the Bond-length in some N,O-Dibenzoylhydroxylamines on the Torsion of the Carboxylic and Hydroxamic Groups against the Benzene Nuclei. The Crystal Structures of N,O-Dibenzoyl-(C14H11NO3), N,O-Bis(2-chlorobenzoyl)-(C14H9Cl2NO3), N-BenzoylO-p-toluoyl- (C15H13NO3), and N-Benzoyl-O-o-toluoylhydroxylamines (C15H13NO3)The crystal structures of four N,O- dibenzoylhydroxylamines - 1: N,O-dibenzoylhydroxylamine (C14H11NO3), 2: N,O- bis(2-chlorobenzoyl)hydroxylamine (C14H9Cl2NO3), 3: N-Benzoyl-O-p toluoylhydroxylamine (C15H13NO3), 4: N-benzoyl-O-o- toluoylhydroxylamine (C15H13NO3) - have been determined by X-ray techniques, using direct methods for phase determination. The torsion angles ϕ of the C—C- bonds between the phenyl groups and the hydroxamic acid groups or the carboxylic groups, respectively, have been calculated. The values of the intramolecular distances of these bonds, plotted versus cos2 ϕ, can be approximated by a straight line. Extrapolating to ϕ = 90°, the pure sp2-sp2-C—C-single-bond is found to be 1.513 Å.
    Notes: Die Kristallstrukturen von vier N,O- Dibenzoylhydroxylaminen - 1: N,O-Dibenzoylhydroxylamin (C14H11NO3), 2: N,O -Bis(2-chlorbenzoyl)hyroxylamin (C14H9Cl2NO3), 3: N-Benzoyl-O-p-toluoylhydroxylamin (C15H13NO3), 4: N- Benzoyl-O-o-toluoylhydroxylamin (C15H13NO3) - wurden röntgenographisch unter Anwendung direkter Methoden zur Lösung des Phasenproblems bestimmt. Die C—C- Bindungslängen zwischen den Phenylgruppen einerseits und den Hydroxamsäure- bzw. Carboxylatgruppen andererseits lassen sich als Funktion der Verdrillungswinkel ϕ dieser Bindung durch eine Gerade darstellen, wenn man die Bindungslängen gegen cos2 ϕ aufträgt. Der reine sp2-sp2-C—C- Einfachbindungsabstand (ϕ = 90°) ist danach 1.513 Å.
    Additional Material: 10 Ill.
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    Eine neue Synthese für Tetracyclo[3.3.0.02,8.04,6]octan-3-one durch intramolekulare [2π + 2 σ]-Thermocycloaddition (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 680-685 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of Tetracyclo[3.3.0.02.8.04.6]octan-3-ones by Intramolecular Thermal [2π + 2σ]-CycloadditionThe synthesis of the tetracyclooctanone 19 by thermolysis of the tricyclic acetal 15 and subsequent removal of the acetal group is described. Thus, a third synthetic access to this system is now available. The reaction involves the cycloaddition of a thermally ring-opened cyclopropane to a double bond.
    Notes: Die Synthese des Tetracyclooctanons 19 durch Thermolyse des tricyclischen Acetals 15 und anschließende Entacetalisierung wird beschrieben. Damit bietet sich ein dritter synthetischer Zugang zu diesem System an. Die Reaktion beinhaltet die Cycloaddition eines thermisch ringgeöffneten Cyclopropans an eine Doppelbindung.
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    Notiz zur Alkylierung des Dithizons (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 717-720 
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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.19741070247
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    Notiz zur thermischen Valenzisomerisierung des Norpinens (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 731-734 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070251
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    Pteridine, LX. Synthese und Oxidationsverhalten von 7,8-Dihydroxanthopterinen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 785-795 
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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: Pteridines, LX. Synthesis and Autoxidation of 7, 8-DihydroxanthopterinsThe synthesis of 7,8-dihydroxanthopterin (18) and of various N- and C-methyl derivatives (19-27, 30) is described. Their pKa values and u.v. spectra have been determined and the behaviour during autoxidation has been investigated. The monoanions are subject to autoxidation which is catalysed strongly by ammonia and primary amines. A mechanism for the autoxidation is discussed in which the existence of various intermediates is based on the oxidative behaviour of differently blocked N- und C-methyl derivatives.
    Notes: Die Synthese des 7,8-Dihydroxanthopterins (18) und verschiedener N- und C-Methyl-Derivate (19-27, 30) wird beschrieben. Ihre pKa-Werte und UV-Spektren werden bestimmt und ihr Autoxidationsverhalten untersucht. Die Monoanionen unterliegen der Autoxidation, welche durch Ammoniak und primäre Amine stark katalysiert wird. Ein Mechanismus wird diskutiert und verschiedene Zwischenprodukte anhand von blockierten N- und C-Methyl-Derivaten wahrscheinlich gemacht.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070305
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    Die Kristall- und Molekülstruktur des 6,6-Bis(dimethylamino)fulvens (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 832-837 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of 6,6-Bis(dimethylamino)fulvene6,6-Bis(dimethylamino)fulvene crystallizes in the space group Pn21a, the lattice constants being ao = 13.344 Å, bo = 7.844 Å and co = 9.438 Å. The structure has been solved by superposition and by direct methods in the space group Pnma. The structure was refined by block-diagonal-least-squares to R = 0.037.
    Notes: Das 6,6-Bis(dimethylamino)fulven kristallisiert in der Raumgruppe Pn21a mit den Gitter-konstanten ao = 13.344 Å, bo = 7.844 Å und co = 9.438 Å. Die Struktur wurde durch Superposition und anschließende Resymmetrisierung der Patterson-Funktion und mit direkten Methoden in der zentrosymmetrischen Obergruppe Pnma gelöst.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070309
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    Brom-Lithium-Austausch an Vinyl- und Aryl-bromiden mit tert-Butyllithium Zur Ringerweiterung über Dibromcarbenaddukte (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 847-853 
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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: Bromine/Lithium Exchange in Vinyl and Aryl Bromides with tert-Butyl Lithium. On the Ring Enlargement via Dibromocarbene AdductsTwofold molar excess of tert-butyl lithium replaces vinylic and arylic bromine by lithium. The tert-butyl bromide formed is dehydrohalogenated rapidly to isobutene by tert-butyl lithium even at very low temperatures. Transformation of 1-bromo-1-cyclooctene and - cyclononene via the lithium derivatives to vinyl thioethers 1d, e, and i in high yields opens up a simple alternative route from olefin dibromocarbene adducts to ring enlarged ketones. The bromobenzenes 2a and 3a reveal that the Br/Li-exchange described here is not accompanied by arine formation; it is feasible even in the presence of sensitive benzylic CH2-groups as present in 3.
    Notes: Vinylisch und an Aromaten gebundenes Brom läßt sich quantitativ mit zweifachem molarem Überschuß an tert-Butyllithium gegen Lithium austauschen. Das entstehende tert-Butylbromid wird selbst bei tiefen Temperaturen von tert-Butyllithium rasch zu Isobuten dehydrohalogeniert. Die Überführung von 1-Brom-1-cycloocten und -1-cycloneone in Vinylthioäther 1d, e und i über die Lithiumderivate ist in hoher Ausbeute möglich und eröffnet einen einfachen Weg von Dibromcarbenaddukten an Olefine zu ringerweiterten Ketonen. Am Beispiel der Brombenzole 2a und 3a wird gezeigt, daß der hier beschriebene Br/Li-Austausch nicht von Arin-Bildung begleitet und auch in Gegenwart der empfindlichen benzylischen CH2-Gruppe von 3 durchführbar ist.
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    URL: http://dx.doi.org/10.1002/cber.19741070311
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    Über N-Vinylimidazolcarbonsäureester (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 892-897 
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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-VinylimidazolecarboxylatesN-Vinylation of imidazolecarboxylates with vinyl acetate leads to the formation of the N-vinylimidazoles 3a, 3b, 6, 8a, 8b und 9a. The structures are determined by mass and n.m.r. spectra. 3a, 6, 8a are polymerizable.
    Notes: Durch N-Vinylierung von Imidazolcarbonsäureestern mit Vinylacetat werden die N-Vinylimidazole 3a, 3b, 6, 8a, 8b und 9a, erhalten. Die Strukturen werden mit Hilfe von NMR-und Massen-Spektren gesichert. 3a, 6, 8a und 8bsing polymerisationsfähig.
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    URL: http://dx.doi.org/10.1002/cber.19741070316
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    Heterocyclisierungen, XIII. Neue polycyclische Pyrimidine mit Brückenkop-Stickstoff (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 929-936 
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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: Heterocyclizations, XIII. New Polycyclic Pyrimidines with Bridge-Head NitrogenThe base-catalized condensation of 2,3,3-trimethyl-3H-benz[f]indole (9) with dielectrophilic iso(thio)cyanates to polycyclic pyrimidines with bridge-head nitrogen (11, 15, 16) in most cases involves preliminary formation of 1: 2 adducts followed by elimination of diacylamides. Contrary to this the less nucleophilic 2,3,3-trimethyl-3H-pyrrolo [2,3-b]pyridine (20) affords the analogue pyrimidines by intermediacy of 1:1 adducts and elimination of water or ethanol solely.
    Notes: Die basenkatalysierte Kondensation von 2,3,3-Trimethyl-3H-benz[f] indol (9) mit dielektrophilen Iso(thio)cyanaten zu polycyclischen Pyrimidinen mit Brückenkopf-Stickstoff (11, 15, 16) verläft meist über die Bildung von 1:2-Addukten als Zwischenstufe und Eliminierung von Diacylamiden. Dagegen liefert das weniger nucleophile 2,3,3-Trimethyl-3 H-pyrrolo[2.3-b]-pyridin (20) analoge Systeme (22, 23) ausschließlich über 1: 1-Addukte und Eliminierung von Wasser bzw. Äthanol.
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    Alkaloide aus Rhamnaceen, XVIII. Amphiin-F, -G und -H, weitere Peptidalkaloide aus Ziziphus amphibia A. Cheval (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 686-697 
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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: Alkaloids from Rhamnaceae, XVIII. Amphibine-F, -G and -H, further Peptide Alkaloids from Ziziphus amphibia A. Cheval.From the complex mixture of crude alkaloids from Ziziphus amphibia A. Cheval., in addition to the already described Amphibines-A, -B, -C, -D and -E, three further peptide alkaloids Amphibine-F, -G and -H have been isolated and their structures elucidated (1-3). Amphibine-F and -G (1, 2) belong to the class of cyclic peptide alkaloides having a fourteen-membered ring system made up from trans-3-hydroxyproline, p-hydroxystyrylamine and an α-aminoacid. Amphibine-H (3) has a thirteen-membered ring system formed from 5-hydroxy-2-methoxystyrylamine and the aminoacids trans-3-hydroxyproline and phenylalanine.
    Notes: Aus dem komplexen Rohbasengemisch von Ziziphus amphibia A. Cheval. wurden neben den bereits beschriebenen Amphibinen-A, -B, -C, -D und -E drei weitere Peptidalkaloide Amphibin-F, -G und -H isoliert und in der Struktur geklärt (1-3). Die Amphibine-F und -G (1, 2) zählen zu den Cyclopeptidalkaloiden mit 14 gliedrigem Ringsystem aus trans-3-Hydroxyprolin, p-Hydroxystyrylamin und einer α-Aminosäure. Das Amphibin-H (3) weist ein 13 gliedriges Ringsystem auf, das aus den Aminosäuren trans-3-Hydroxyprolin und Phenylatanin sowie aus 5-Hydroxy-2-methoxystyrylamin gebildet wird5).
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    Über die Darstellung neuer Chlorformamidine (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 698-705 
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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: On the Preparation of New ChloroformamidinesAction of phosphine/carbon tetrachloride or dichlorotriphenylphosphorane on N,N,N′-trisubstituted ureas leads to the formation of even such chloroformamidines which are not or only difficultly obtainable by the conventional methods. The spectroscopic and analytic data of the new compounds are given.
    Notes: Durch Einwirkung von Phosphin/Tetrachlorkohlenstoff oder von Dichlortriphenylphos-phoran auf N,N,N′-trisubstituierte Harnstoffe können auch solche Chlorformamidine dargestellt werden, die nach den bisherigen Methoden nicht oder nur schwer zugänglich sind. Die spektroskopischen und analytischen Daten der neuen Verbindungen sind angegeben.
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    Notiz über eine verbesserte Methode zur spezifischen Freisetzung oder Acylierung primärer Hydroxylgruppen ausgehend von pertrimethylsilylierten Polyolen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 721-724 
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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.19741070248
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    Notiz zur transanularen n/π-Wechselwirkung in 2,5-Dihydrofuran (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 725-726 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070249
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    Heterosubstituierte Fulvene, VIII. Indeno[2,1-c]-1,2-dithiole, eine Gruppe neuer Pseudoazulene (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 739-744 
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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: Heterosubstituted Fulvenes, VIII. Indeno[2,1-c]-1,2-dithioles, a Group of New PseudoazulenesAcylation of 2-pyrrolidinoindene (4) with carboxylic acid chlorides and subsequent hydrolysis leads to the 1-acyl-2-indanones 6, which have been condensed with diacetyl disulfide in aequous perchloric acid/acetic acid to afford the 8H-indeno[2,1-c]-1,2-dithiolium-perchlorates 7. These are deprotonated with N-ethyldiisopropylamine to yield the indeno[2,1-c]-1,2-dithioles 10, a group of new pseudoazulenes.
    Notes: Acylierung von 2-Pyrrolidinoinden (4) mit Carbonsäurechloriden und nachfolgende Verseifung liefert die 1-Acyl-2-indanone 6, die mit Diacetyldisulfid in wäßriger Perchlorsäure, Eisessig zu den 8H-Indeno[2,1-c]-1,2-dithiolium-perchloraten 7 kondensieren. Letztere lassen sich durch N-Äthyldiisopropylamin zu den Indeno[2,1-c]-1,2-dithiolen 10, einer Gruppe neuer Pseudoazulene, deprotonieren.
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    Stereochemie und reaktives Verhalten tetrahalogenierter 2,3-Diazabicyclo[3.2.0]hept-2-ene und Bicyclo[2.1.0]pentane (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 759-770 
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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 and Reactivity of Tetrahalogenated 2,3-Diazabicyclo[3.2.0]hept-2-enes and Bicyclo [2.1.0] pentanesThe addition of diazoalkanes to tetrahalogenated cyclobutenes 1-3 leads to 6,6,7,7-tetrahalo-2,3-diazabicyclo[3.2.0]hept-2-enes 4-8, the structure and stereochemistry of which are determined by means of n. m. r. spectroscopy. Thermal decomposition of 4, 5, and 8 in boiling toluene affords the tetrahalobicyclo[2.1.0]pentanes 9, 10, and 12 in good yields. Under the same conditions 7 decomposes in a stereospecific manner to form 11 and small amounts of 13. Sodium methoxide converts 9-11 into the cyclobutenes 14 and 15. Under the influence of sulfuric acid 10 forms the cyclobutenedione 16 or a mixture of cyclopentenones 18, 19 depending on the reaction conditions.
    Notes: Addition von Diazoalkanen an die tetrahalogenierten Cyclobutene 1-3, führt zu 6,6,7,7-Tetrahalogeno-2,3-diazabicyclo[3.2.0]hept-2-enen 4-8, deren Konstitution und Stereochemie auf NMR-spektroskopischem Weg ermittelt wurde. Durch thermische Zersetzung der Bicyclen 4,5 und 8 in siedendem Toluol erhält man in guten Ausbeuten Tetrahalogenobicyclo-[2.1.0]pentane 9,10 und 12. Unter gleichen Bedingungen entstehen aus 7 in stereospezifischer Reaktion 11 sowie geringe Mengen des Cyclobutens 13. Mittels Natriummethylat werden die Bicyclen 9-11 zu den Cyclobutenen 14, 15 abgebaut; unter dem Einfluß von konz. Schwefelsäure entsteht aus 10 je nach Reaktionsbedingungen das Cyclobutendion 16 bzw. ein Gemisch der Cyclopentenone 18 und 19.
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    Ein Eintopfverfahren zur Überführung von Aldehyden in Nitrile (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1221-1227 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conversion of Aldehydes into Nitriles without Isolation of IntermediatesAldehydes are converted into nitriles without isolation of the intermediates by treating their oximes with carbodiimides in the presence of copper(II)ions and triethylamine. The entire process requires 3 hours at room temperature; it is unsuccessful if the oxime does not form or is consumed by competition reactions.
    Notes: Aldehyde können ohne Isolierung von Zwischenprodukten in Nitrile übergeführt werden, indem ihre Oxime in Gegenwart von Kupfer(II)-Ionen und Triäthylamin mit Hilfe von Carbodiimiden dehydratisiert werden. Der gesamte Prozeß erfordert bei Raumtemperatur durchweg 3 Stunden. Das Verfahren versagt, wenn die Oximbildung gestört ist oder das Oxim Konkurrenzreaktionen eingeht.
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    URL: http://dx.doi.org/10.1002/cber.19741070418
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    Synthese und Reaktivität von Silicium-Übergangsmetallkomplexen, V. Die modifizierte Alkalisalz-Eliminierungsmethode  -  ein genereller Weg zu Komplexen mit Silicium-Übergangsmetall-Struktureinheiten (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 979-995 
    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 Reactivity of Silicon Transition Metal Complexes, V. The Modified Alkali Salt Elimination Method  -  a General Procedure for the Synthesis of Silicon Transition Metal CompoundsThe heterogeneous reaction of the sodium carbonylmetallates Na[Fe(CO)2π-C5H5], Na[M(CO)3π-C5H5] (M=Mo, W), and Na[Mn(CO)5] with various halo- and organohalosilanes leads to the formation of the corresponding silyl complexes. The new compounds are characterized by spectroscopy and the chemical properties are described. The results of a decomposition study of the trimethylsilyl-VIB transition metal complexes are discussed in connection with former synthetic experiments. Exchange reactions of these species with heterosiloxanes can be used for a qualitative estimation of relative metal-metalloid bond reactivity.
    Notes: Die Umsetzung der komplexen Metallate Na[Fe(CO)2π-C5H5], Na[M(CO)3π-C5H5] (M=Mo, W) und Na[Mn(CO)5] mit verschiedenen Halogen- und Organohalogensilanen führt in heterogener Reaktion zu den Silylkomplexen dieser Metalle. Die neuen Verbindungen werden spektroskopisch charakterisiert und ihre chemischen Eigenschaften beschrieben. Die Ergebnisse einer Zerfallsstudie der Trimethylsilyl-VIB-Übergangsmetallkomplexe werden im Zusammenhang mit früheren Syntheseversuchen diskutiert. Der Verlauf von Austauschreaktionen der gleichen Verbindungen mit Heterosiloxanen (Ge, Sn) ermöglicht eine qualitative Abschätzung der Reaktivität der Metall- Metalloideinheit.
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    Untersuchungen an 4-Pyronen, 51 Aminoalkylierung von Chromonen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1057-1065 
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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 4-Pyrones, 51. Aminoalkylation of ChromonesThe aminoalkylation of 2-methylchromones (1b, e and 2b, c) leads to the formation of benzopyrano[3.2-c]pyridinium chlorides (9a-d and 11a-e).
    Notes: Die Aminoalkylierung von 2-Methylchromonen (1b, e sowie 2b, c) führt zu Benzopyrano-[3.2-c]pyridinium-chloriden (9a-d sowie 11a-e).
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19741070334
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    Berichtigung (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1069-1069 
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    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.19741070336
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    Massenspektrometrische Untersuchung von Amiden, VII Intramolekulare Wechselwirkungen bifunktioneller Gruppen bei der elektronenstoßinduzierten Fragmentierung von Piperididen und Piperideiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1081-1091 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mass Spectrometric Investigation of Amides, VII. Intramolecular Interactions of Bifunctional Groups in the electron Impact Induced Fragmentation of Piperidides and PiperideidesThe activation energy ∊ for the electron impact induced splitting of the N-carbonyl bond in bifunctional amides is estimated. A clear correlation is shown of ∊ with the ring size of the transition state and the nucleofuge or nucleophilic properties of the nitrogen groups. Furtheron by means of [D]-labelled model compounds selective hydrogen migrations have been established.
    Notes: Die Aktivierungsenergie ∊ für die elektronenstoßinduzierte Spaltung der N-Carbonylbindung bifunktioneller Amide wird bestimmt. Es ergibt sich ein klarer Zusammenhang von ∊ mit der Ringgröße des Übergangszustandes und den nucleofugen bzw. nucleophilen Eigenschaften der Stickstoffgruppen. Ferner werden mit Hilfe [D]-markierter Modellverbindungen selektive Wasserstoffübertragungen nachgewiesen.
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  • 74
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    Über die Natur des Benzonorbornen-2-yl-Kations, II. Solvolyse von Isopropyliden-substituierten Benzonorbornen-2-yl-Estern (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1126-1135 
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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: On the Nature of Benzonorbornen-2-yl Cations, II. Solvolysis of Isopropylidene-substituted benzonorbornen-2yl EstersThe 2-epimeric at C-7 and C-3 substituted benzonorbornenols 4a, 6a, 7a and 8a are synthesized. The rate of solvolysis of the tosylates 4b and 6b is measured in acetic acid, that of the 3,5-dinitrobenzoates 7b and 8b in 90% dioxane. The solvolysis products are determined in 80% acetone puffered with 2,6-lutidine. The epimeric 7-isopropylidene derivatives 4b and 6b solvolyse by a different mechanism; the exo derivative 4b reacts exclusively with assistance of the benzene ring, the endo compound by participation of the homoallylic double bond. The epimeric 3-isopropylidene derivatives 7b and 8b solvolyse to a common intermediate allylic ion 10. The kexo/kendo ratio is reduced to 9 due to the presence of this neighbouring group, which is a measure of the steric factor in the secondary benzonorbornen-2-yl system.
    Notes: Die epimeren Benzonorborneole 4a und 6a sowie 7a und 8a werden synthetisiert. Die Solvolysegeschwindigkeit der Tosylate 4b und 6b wird in Eisessig, die der 3,5-Dinitrobenzoate 7b und 8b in 90 proz. Dioxan gemessen. Die Reaktionsprodukte werden in 80 proz., mit 2,6-Lutidin gepuffertem Aceton bestimmt. Die epimeren 7-Isopropyliden-Verbindungen 4b und 6b solvolysieren nach einem unterschiedlichen Mechanismus; die exo-Verbindung 4b reagiert ausschließlich mit Beteiligung des Aromaten, die endo-Verbindung 6b mit der der Isopropyliden-Doppelbindung. Die epimeren 3-Isopropyliden-Verbindungen 7b und 8b solvolysieren zu einem gemeinsamen Allyl-Ion 10 als produktbestimmende Zwischenstufe. Das Verhältnis kexo/kendo wird durch diese Nachbargruppe auf 9 herabgesetzt, welches ein Maß für den sterischen Anteil des sekundären Benzonorbornen-2-yl-Systems ist.
    Additional Material: 1 Ill.
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    Übergangsmetall-Carben-Komplexe, LXXII. Spaltung der Doppelbindung von 1-Vinyl-2-pyrrolidon und β-substituierten 1-Vinylpyrrolidonen bei der Umsetzung mit Pentacarbonyl(methoxyphenylcarben)chrom(0) (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1156-1161 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbene Complexes, LXXII. Cleavage of the Double Bond of 1-vinyl-2-pyrrolidone and β-Substituted 1-Vinylpyrrolidones by Reaction with Pentacarbonyl(methoxyphenylcarbene)chromium(0)Pentacarbonyl(methoxyphenylcarbene)chromium(0) reacts with 1-vinyl-2-pyrrolidone to form α-methoxystyrene by transfer of a methylene group to the carbene moiety. The origin of the transfered methylene group is proved by using methylsubstituted 1-vinylpyrrolidones. The reaction products are identified by their i.r., 1H n.m.r., and mass spectra. As reaction mechanism a cyclic transition state is proposed, which explains the breaking and following formation of a double bond analogously to the heterolytic fragmentation according to Grob.
    Notes: Bei der Umsetzung von Pentacarbonyl(methoxyphenylcarben)chrom(0) mit 1-Vinyl-2-pyrrolidon entsteht durch Übertragung einer Methylengruppe auf den Carben-Rest α-Meth-oxystyrol. Durch Einsetzen methylsubstituierter 1-Vinylpyrrolidone wird die Herkunft der übertragenen Methylengruppe bewiesen. Die Produkte werden anhand ihrer IR-, 1H-NMR- und Massenspektren identifiziert. Als Reaktionsmechanismus wird ein cyclischer Übergangszustand vorgeschlagen, der - in Analogie zur heterolytischen Fragmentierung nach Grob - die Spaltung und Neuknüpfung einer Doppelbindung erklärt.
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    Photochemische Reaktionen, XXIII. Über Photocyclisierungen von 9-Benzylidenxanthenen und 9-Benzylidenthioxanthenen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1207-1212 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemical Reactions, XXIII. The Photocyclisation of 9-Benzylidenexanthenes and 9-BenzylidenethioxanthenesDehydrocyclisations of the 9-benzylidenexanthenes in u.v. or sunlight (6a-6d→7a-7d) were realized. 6 may be considered as derived from stilbene, and 7 as derived from phenanthrene. Therefore the photoprocess 6→7 is analogue to the photoprocess cis-stilbene → phenanthrene.
    Notes: Dehydrocyclisierungen der Benzylidenxanthene im UV-oder Sonnenlicht (6a-6b→7a-7d) wurden durchgeführt. Da 6 als substituierte cis-Stilbene und 7 als substituierte Phenanthrene aufgefaßt werden können, liegen Analogiereaktionen zu dem Photoprozeß cis-Stilben → Phenanthren vor.
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    URL: http://dx.doi.org/10.1002/cber.19741070416
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    Darstellung und dynamisches Verhalten von Mono- cyclopentadienylarsinen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1228-1234 
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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 and Dynamic Behaviour of Mono-cyclopentadienylarsinesMono-cyclopentadienylarsines (3a-e) are synthesized by the reaction of cyclopentadienyl-trimethylsilane (1) or cyclopentadienyllithium (5) with the halogenoarsines 2a-e. They are very sensitive against air and moisture and thermally unstable. The cp-ligands are σ-bonded; the molecules have a fluxional structure. The rapidity of the degenerate metallotropic rearrangements is influenced by the other ligands on the arsenic atom.
    Notes: Mono-cyclopentadienylarsine (3a-e) werden durch Umsetzung von Cyclopentadienyl-trimethylsilan (1) oder Cyclopentadienyllithium (5) mit den Halogenarsinen 2a-e dargestellt. Sie sind äußerst luft- und feuchtigkeitsempfindlich und thermisch instabil. Es liegen σ-gebundene Cp-Liganden und Moleküle mit fluktuierender Struktur vor. Die Geschwindigkeit der entarteten metallotropen Umlagerungen wird durch die anderen Liganden am Arsenatom beeinflußt.
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    Enhydrazine, 9. 1-Alkyl-3-hydroxypyrazole aus Hydrazonen oder Hydrazinen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1318-1328 
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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: Enehydrazines, 9. 1-Alkyl-3-hydroxypyrazoles from Hydrazones or HydrazinesReaction of dimethyl acetylendicarboxylate with hydrazinen oder Alkyl hydrazonen gives the methyl 1-alkyl-3-hydroxy-5-pyrazolecarboxylats 9 and 13a-e, subsequent saponification and decarboxylation gives the 1-alkyl-3-hydroxypyrazoles 11 and 15a-e. The cyclization of 13f to lactone 19a is a structure proff. Starting from benzaldehyde hydrazones, 2-pyrazoline-4,5-dicarboxylic esters are the main products.
    Notes: Durch Umsetzung von Acetylendicarbonsäure- dimethylester mit Hydrazinen oder Alkyl-hydrazonen erhält man die 1-Alkyl-3-hydroxy-5-pyrazolcarbonsäure-methylester 9 und 13a-e, durch Verseifung und Decarboxylierung hieraus die 1-Alkyl-3-hydroxypyrazole 11 und 15a-e. Die Cyclisierung von 13f zum Lacton 19a ist strukturbeweisend. Bei Verwendung von Benzaldehyd-hydrazonen entstehen hauptsächlich 2-Pyrazolin-4,5- dicarbonsäureester.
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    Elektrophile Addition von Dischwefeldichlorid an Alkine, 3. Umsetzung asymmetrisch substituierter Alkine mit Dischwefeldichlorid (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1334-1343 
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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: Electrophilic Addition of Disulfur Dichloride to Alkynes, 3. Reaction of Asymmetric of Asymmetric Substituted Alkynes with Disulfur DichlorideDisulfur dichloride adds to the triple bond of asymmetric substituted alkynes to afford vinyl sulfides, which are constitution isomers. Substituents R with a negative I-effect yield „Markownikof“ products whereas a positive I-effect leads to the formation of „anti-Markownikoff“ products. The addition is always trans. The obtained sulfides are oxidized with H2O2 in glacial acetic acid to yield the corresponding sulfones.
    Notes: Die bei der elektrophilen Addition von Dischwefeldichlorid an asymmetrische Alkine gebildeten Vinylsulfide sind Konstitutions -Isomere. Substituenten R mit negativem Induktionseffekt führen zu „Markownikoff“-Produkten, während ein positiver I-Effekt „anti-Markownikoff“-Orientierungen liefert. In allen Fällen erfolgt eine trans-Addition. Die erhaltenen Sulfide werden nach der Oxidation mit Wasserstoffperoxid/Eisessig als Sulfone isoliert.
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    Oxidative Additionsreaktionen von Nitroalkanen an Tetrakis(triphenylphosphin)platin(0) (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1371-1379 
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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: Oxidative Addition Reactions of Nitroalkanes to Tetrakis(triphenylphoshine)platinum(0)The oxidative addition of nitromethane to Pt(PPh3)4 in polar protic solution provides a convenient and safe method for the preparation of trans-(Ph3P) 2Pt(CNO)2 Pt(CNO2)(3). From Pt(PPh3)4 and nitromethane or 2-nitropropane cis-(Ph3P) 2Pt(NO2)2 (2) is obtained. The reactions of Pd(PPh3)4 or Rh(PPh3)2CO)Cl with CH3NO2 or some of its derivatives afford isocyanato compounds. Formaidoxime hydrochloride reacts with Pt(PPh3)4 to give trans-(Ph3P)2Pt-(CN)Cl (4).
    Notes: Die oxidative Addition von Nitromethan an Pt(PPH3)4 in polarem, protischem Medium liefert gefahrlos und in guter Ausbeute trans-(Ph 3P)2Pt(CNO)2 (3). Aus Pt(PPh3)4 und Nitromethan bzw. 2-Nitropropan wird cis-(Ph3P)2Pt(NO2)2 (2) erhalten. Die Umsetzungen von Pd(PPh 3)4 oder Rh(PPh3)2(CO)Cl mit Nitromethan oder Methylnitrolsäure führen zu Isocyanatoverbindungen. Formaldoxim-hydrochlorid reagiert mit Pt(PPh 3)4 zu trans-(Ph3P)2Pt(CN)Cl (4).
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    Botrydial, ein Sesquiterpen-Antibiotikum aus der Nährlösung des Pilzes Botrytis cinerea (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1720-1730 
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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: Botrydial, a Sesquiterpene Antibiotic from the Culture Solution of the Fungus Botrytis cinereaThe antibiotic botrydial (3) and its dihydro derivative (1) were isolated from the culture solution of the fungus Botrytis cinerea. Their structural formulas were elucidated by means of a series of chemical transformations together with the application of spectroscopic methods, especially a detailed analysis of the n.m.r. spectra. The basic skeleton of botrydial is a bicyclic, non-isoprenoid sesquiterpene system.
    Notes: Aus der Nährlösung des Pilzes Botrytis cinerea wurden das antibiotisch wirksame Botrydial (3) und sein Dihydroderivat (1) isoliert. Durch eine Folge chemischer Umwandlungen, verbunden mit der Anwendung spektroskopischer Methoden, insbesondere einer detaillierten Analyse der NMR-Spektren, wurden ihre Konstitutionsformeln abgeleitet. Botrydial liegt ein bicyclisch nicht-isoprenoides Sesquiterpenskelett zugrunde.
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    Natürlich vorkommende Terpen-Derivate, XXXIV. Notiz über die Synthese des Furanoeremophilans (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1767-1768 
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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.19741070535
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    Natürlich vorkommende Terpen-Derivate, XXXVI. Synthese von 8-Hydroxybrickellol und Dehydronerol-isovalerat (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1773-1776 
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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: Naturally Occuring Terpene Derivatives, XXXVI. Synthesis of 8-Hydroxybrickellol and Dehydronerol isovalerateThe sesquiterpene 7 named 8-hydroxybrickellol as well as the isovalerate of dehydronerol (14) have been synthesized.
    Notes: Das 8-Hydroxybrickellol benannte Sesquiterpen 7 sowie der Isovaleriansäureester des Dehydronerols (14) werden synthetisch dargestellt.
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    Die Reaktionen von Phosphor-yliden mit überschüssigem Alkohol und mit Alkanthiol (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1420-1427 
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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 Reactions of Phosphorus Ylids with Excess Alkohol and AlkanethiolThe alkoxytetraalkylphosphoranes of the formula R4POR′, obtained from equimolar amounts of ylid and alkohol, which contain pentacoordinate phosphorus atoms, are converted into ionic products (1 - 7) by addition of excess alkohol. In these compounds phosphonium cations R4P⊕ are accompanied by hydrogen-bonded hydrogenalkoholate anions of the types [R′O…H…OR′]⊖, [H2(OR′)3]⊖, and [H3(OR′)4]⊖. This structure is proposed on the basis of n.m.r., i.r., and Raman-spectroscopic data. With ylids and alkanethiols only salt-like products R4P⊕RS⊖ are formed.
    Notes: Die aus äquimolaren Mengen von Yliden und Alkoholen zugänglichen, kovalent gebauten Alkoxytetraalkylphosphorane R4POR′ mit pentakoordinierten Phosphoratomen werden durch Addition von überschüssigem Alkohol in die Produkte 1 - 7 verwandelt, in welchen Phosphonium-Kationen R4P⊕ den wasserstoffbrückenverknüpften Hydrogenalkoholat-Anionen vom Typ [R′O…H…OR′]⊖, [H2(OR′)3]⊖ und [H3(OR′)4]⊖ gegenüberstehen. Der Strukturvorschlag stützt sich auf NMR-, IR- und Raman-spektroskopische Untersuchungen. Aus Yliden und Alkanthiolen entstehen nur die salzartigen Phosphonium-alkanthiolate R4 P⊕RS⊖.
    Type of Medium: Electronic Resource
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    Umlagerungen 3-substituierter Norbornandiazonium-Ionen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1472-1482 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of 3-Substituted Norbornanediazonium Ions3-Oxonorbornane-2-endo-diazonium ions (1), generated by acid-catalyzed decomposition of 3-diazonorcamphor (5) in alcoholic solutions, produce derivatives of endo-bicyclo[2.2.1]heptane 3 and bicyclo [3.1.1]heptane derivatives 4, varying with the nucleophilicity of the solvent. This suggests the 7-bridged ion 2 as intermediate, which plays also an important part in the deamination of 3,3-dimethoxynorcamphor tosylhydrazone (16) in alkaline solutions as shown by the formation of 3 and 4. In the alkaline deamination of 3,3- dimethoxy-5-norbornen-2-on tosylhydrazone (32) in methanol the homoallylic ion 34 is dominating.
    Notes: 3-Oxonorbornan-2-endo-diazonium-Ionen (1), erzeugt durch sauer katalysierte Zersetzung von 3-Diazonorcampher (5) in alkoholischen Lösungen, ergaben endo-Bicyclo[2.2.1]heptan-3 und Bicyclo[3.1.1]heptan-Derivate 4, deren Menge von der Nucleophilie des eingesetzten Lösungsmittels abhängig ist. Dies läßt das 7-verbrückte Ion 2 als Zwischenstufe vermuten, welches auch bei der Desaminierung des 3,3-Dimethoxynorcampher-tosylhydrazons (16) in alkalischen Lösungen eine entscheidende Rolle spielt, wie die Bildung der Produkte 3 und 4 beweist. Bei der alkalischen Desaminierung des 3,3-Dimethoxy-5-norbornen-2-on-tosylhydrazons (32) in Methanol ist jedoch die Homoallylumlagerung zum Kation 34 produkt-bestimmend.
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    Derivate des Guanidins mit N—S- und N—P-Bindungen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1536-1544 
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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: Derivatives of Guanidines Containing Phosphorus and SulfurN-Chloroguanidines 1 react with tervalent phosphorous compounds or with sulfides to yield N-guanylphosphine imidium (3) or sulfimidium salts (9). Dehydrohalogenation gives the respective N-guanyl phosphine imides and sulfimides. The structure and reactions of these compounds are discussed.
    Notes: Die Umsetzung von N-Chlorguanidinen 1 mit tervalenten Phosphorverbindungen sowie Sulfiden führt zu N-Guanylphosphinimidium- (3) bzw. -sulfimidium-Salzen (9). Durch Dehydrohalogenierung werden die entsprechenden Phosphinimide und Sulfimide erhalten. Die Eigenschaften dieser Verbindungen - insbesondere die Struktur-und Bindungsverhältnisse-sowie ihre Reaktionen werden untersucht.
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    URL: http://dx.doi.org/10.1002/cber.19741070514
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    Konformationsanalyse, III. exo-Anomerer Effekt und Circulardichroismus von Glycopyranosylaziden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1568-1578 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conformational Analysis, III. exo-Anomeric Effect and Circular Dichroism of Glycopyranosyl AzidesTetra-O-acetyl-aldopentopyranoses and penta-O-acetyl-aldohexopyranoses react readily with trimethylsilyl azide in the presence of BF3 or SnCl4 to afford the corresponding glycosyl azides 1a - 11 (table 1). Only the anomeric glycosyl azide having the azido group „trans“ to the 2-acetoxy group is obtained in each case. The polarization of the Cl—Nx and Nx—Nz bonds in glycosyl azides is such that in both cases the dipole is directed toward Nx. It can be deduced that glycosyl azides, like methyl glycopyranosides, should exhibit an exo-anomeric effect which strongly favors the conformers 9 and 12. The application of the azide-octant rule predicts a negative Cotton effect for the α-D-glycosyl azide 12 and a positive effect for the β-D-glycosyl azide 9. Circular dichroism measurements are in good agreement with these predictions, indicating the operation of an exo-anomeric effect in the glycosyl azides.
    Notes: Tetra-O-acetyl-pentopyranosen und Penta-O-acetyl-hexopyranosen setzen sich mit Trimethylsilylazid bei Gegenwart von BF3 oder SnCl4 leicht zu den entsprechenden Glycosylaziden 1a bis 11 um (Tab. 1). Es entsteht stets nur das anomere Glycosylazid, in dem die Azidogruppe und 2-OAc „trans“ zueinander angeordnet sind. In Glycosylaziden sind die Bindungen Cl—Nx und Nx—Nz in der Weise polarisiert, daß der Dipol in beiden Fällen zum Nx weist. Hieraus wird abgeleitet, daß bei Glycosylaziden wie bei Methylglycosiden ein exo-anomerer Effekt wirksam sein sollte, der die Konformeren 9 und 12 stark bevorzugt. Die Anwendung der Azid-Oktantenregel sagt für das α-D-Glycosylazid 12 einen negativen, für das β-D-Glycosylazid 9 einen positiven Cotton-Effekt voraus. Messungen des Circular-dichroismus stimmen mit diesen Voraussagen gut überein, was für einen exo-anomeren Effekt bei Glycosylaziden spricht.
    Additional Material: 2 Ill.
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    Thermisch induzierte Reaktionen von Imidazolderivaten, IV. Die Kinetik der thermischen Umlagerung von 2,4,4-Thriaryl-5-mathylthio-4H-imidazolen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1645-1648 
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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: Thermally Induced Reactions of Imidazole Derivatives, IV. Kinetics of the Thermal Rearrangement of 2,4,4-Triaryl-5-methylthio-4H-imidazolesThe thermal rearrangements of the title compounds 1a - d into the 2,4,5-triarylimidazoles 2 in different solvents and at different temperatures are first order reactions. No linear relation exists between the effect of the p-substituents of the migrating aryl groups on the reaction rates and their Hammett-Brown σ+ values. The solvent has practically no effect on the rearrangement rate of 1c. The activation parameters of the rearrangement 1c → 2c are given.
    Notes: Die thermische Umlagerung der Titelsubstanzen 1a - d in die 2,4,5-Triarylimidazole 2 in verschiedenen Lösungsmitteln und bei verschiedenen Temperaturen folgt einem Geschwindigkeitsgesetz 1. Ordnung. Der Einfluß des p-Substituenten der wandernden Arylgruppe ändert sich nicht linear mit den Hammett-Brownschen σ+-Werten. Das Lösungsmittel hat praktisch keinen Einfluß auf die Umlagerungsgeschwindigkeit von 1c. Die Aktivierungsparameter der Umlagerung 1c → 2c werden angegeben.
    Additional Material: 1 Ill.
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    Vinyl-Kationen, 15. Darstellung und Solvolyse der stereoisomeren 1-Brommethylen-2-methylcyclopropane (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1676-1683 
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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: Vinyl Cations, 15. Preparation and Solvolysis of the Stereoisomeric 1-Bromomethylene-2-methylcyclopropanesThe stereoisomeric 1-bromomethylene-2-methylcyclopropanes (6Z and 6E) are synthesized and their solvolysis rates and products in ethanol/Water mixtures are determined. 6Z and 6E solvolyse at approximately the same rates. Both isomers yield only the rearranged products 12, 14, 16 and 18, which are formed from both isomers in the same ratio. The products as well as the kinetic data are explained by assuming the formation of the stabilized cyclopropylidenemethyl cation 7.
    Notes: Die stereoisomeren 1-Brommethylen-2-methylcyclopropane (6Z und 6E) wurden dargestellt und die Solvolysegeschwindigkeiten sowie die Produkte in Äthanol/Wasser-Gemischen bestimmt. 6Z und 6E solvolysieren dabei etwa mit gleicher Geschwindigkeit. Aus beiden Isomeren entstehen ausschließlich die umgelagerten Produkte 12, 14, 16 und 18 im gleichen Mengenverhältnis. Produktanalyse und Kinetik werden mit der Bildung des stabilisierten Cyclopropylidenmethylkations 7 erklärt.
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    Dispiro[2.0.2.4] deca-7,9-dien und Vergleichsverbindungen: Darstellung, UV-, NMR- und Photoelektronen-spektroskopische Untersuchungen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1684-1701 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dispiro[2.0.2.4]deca-7,9-diene and Related Model Compounds: Synthesis, U.V, N.M.R, and Photoelectron-Spectroscopic InvestigationsDispiro[2.0.2.4]deca-7,9-diene (4) and spiro[2.5]octa-4,6-diene (5 can be obtained from the corresponding monoolefins 6 and 10, respectively, by bromine addition and subsequent dehydrobromination. The u. v. spectra of 5 and 4 with λmax = 269 nm (log ε = 3.4) and 284 nm (3.7), respectively, show bathochromic shifts of their longest wavelength bands as compared to 1,3-cyclohexadiene. An analysis of the 1H n. m. r. chemical shifts and H, H-coupling constants for the olefinic protons in 4 indicates that there is no cyclic electron delocalization in this ring system. The six-membered ring in 4 is only slightly flatter than the one in 1,3- cyclohexadiene. The photoelectron spectroscopic data of 4, 5, spiro[2.5]octane (13), spiro[2.5]oct-4-ene (15), dispiro[2.0.2.4]decane (14), and dispiro[2.0.2.4]dec-7-ene (16) demonstrate the effect of the interaction between π-orbitals and cyclopropyl Walsh-orbitals; an assignment for the first bands in the p. e. spectra of these compounds is proposed.
    Notes: Dispiro[2.0.2.4] deca-7,9-dien (4) und Spiro[2.5]octa-4,6-dien (5) lassen sich aus den entsprechenden Monoolefinen 6 bzw. 10 durch Bromierung und anschließende Dehydrobromierung gewinnen. Die UV-Absorptionen von 5 und 4 mit λmax = 269 nm (log ε = 3.4) bzw. 284 nm (3.7) sind bathochrom verschoben gegenüber denjenigen des 1,3-Cyclohexadiens. Aus einer Analyse der Chemischen Verschiebungen und H,H-Kopplungskonstanten der olefinischen Protonen im 1H-NMR-Spektrum von 4 ist zu schließen, daß 4 kein cyclisch delokalisiertes Elektronensystem enthält. Der Sechsring in 4 ist nur wenig stärker eingeebnet als derjenige im 1,3-Cyclohexadien. Anhand der Photoelektronen-Spektren von 4, 5 sowie Spiro[2.5]octan (13), Spiro[2.5]oct-4-en (15), Dispiro[2.0.2.4]decan (14) und Dispiro[2.0.2.4]dec-7-en (16) wird der Effekt der Wechselwirkung zwischen π-Orbitalen und Cyclopropyl-Walsh-Orbitalen aufgezeigt; für die jeweils ersten Banden in den PE-Spektren dieser Verbindungen wird eine Zuordnung vorgeschlagen.
    Additional Material: 4 Ill.
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    Asymmetrische Hydrierungen mit 1,4-Bis(dimethylamino)- (2S,3S)-und -(2R,3R)-butan-2,3 -diol(DBD)/Lithiumaluminiumhydrid (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1748-1763 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Hydrogenation with 1,4-Bis(dimethylamino)-(2S,3S)- and -(2R,3R)-butane-2,3-dio(DBD)/Lithium Aluminium HydrideThe diaminodiol 6 (DBD) mentioned inthe in the title is readily available in two steps from commercial diethyl tartrate. It reacts with lithium aluminium hydride (LAH) or deuteride to give chirally modified 1:1-complexes which reduce aldehydes, ketones, and ozonides to optically active carbinols in optical yields of up to 75%. Since both enantiomers of DBD are to accessible, both dextro- and levo-rotatory products may be prepared at will. DBD is easily separated from products and recovered without loss of activity. The (-)- DBD-LAH-complex reduces both dialkyl and aryl alkyl ketones to give samples enantiomerically enriched with carbinols of (S)- configuration, while the (+)-DBD-complex acts the other way around. This result is independent of the mode of preparation of the complex, of the ratio of reducing reagent over substrate, of addition of alcohols or water, of reaction temperature, or solvent. The effects of some of these influences upon the optical yields are large. Optimum conditions are given; the efficiency of the DBD-LAH-complex is compared with similar chirally modified LAH derivatives already known. A mechanism explaining the stereochemical results is proposed.
    Notes: Das aus Weinsäureester in zwei Stufen leicht zugängliche, im Titel genannte Diaminodiol 6 (DBD) setzt sich mit Lithiumaluminiumhydrid (LAH) und -deuterid zu chiral modifizierten 1: 1-Komplexen um. Diese reduzieren Aldehyde, Ketone und Ozonide zu opt. aktiven Carbinolen in optischen Ausbeuten bis zu 75%. Da beide Enantiomeren von DBD zugänglich sind, lassen sich gezielt (+)- oder (-)-drehende Produkte darstellen. DBD ist von den Produkten bequem abtrennbar und ohne opt. Verluste zurückgewinnbar. Mit (-)-DBD-LAH- Komplex entstehen Dialkyl- und Alkyl-aryl- carbinole mit (S)-, aus dem enantiomeren Komplex mit (R)-Konfiguration des Überschußenantiomeren. Dies ist völlig unabhängig von Darstellungsmodus des Komplexes, molarem Verhältnis von Reduktionsmittel und Substrat, Zusätzen von Alkoholen oder Wasser, Reaktionstemperatur oder -lösungsmittel. Die Einflüsse dieser Faktoren auf die opt. Ausbeuten, für die optimale Bedingungen angegeben werden, sind indessen zum Teil groß. Vergleiche mit bekannten Komplexen aus LAH und anderen chiralen Liganden werden gezogen. Es wird ein Vorschlag zur Erklärung der stereochemischen Befunde gemacht.
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    Natürlich vorkommende Terpen-Derivate, XXXVII. Synthese des Sesquiterpens aus Elvira biflora DC (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1777-1779 
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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: Naturally Occurring Terpene Derivatives, XXXVII. Synthesis of the Sesquiterpene from Elvira biflora DCThe aromatic sesquiterpene 11 isolated from Elvira biflora DC has been synthesized starting with the p-cresol 2-butenyl ether (1).
    Notes: Das aus Elvira biflora DC isolierte aromatische Sesquiterpen 11 wird ausgehend vom p-Cresol-2-butenyläther (1) synthetisiert.
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    Reaktionsverhalten von Nitril-yliden verschiedener Provenienz (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1823-1834 
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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: Reactivity of Nitrile Ylides of Different OriginThermolysis and photolysis of 2,3-dihydro- 1,4,2λ5-oxazaphospholes 2, photolysis of 1- azetines 3 as well as 1,3-elimination of hydrogen chloride from imidoyl chlorides 4 proceeds via the nitrile ylide intermediate 1. This is deduced from the same product ratio of the isomeric cycloadducts 5:6 on trapping with acrylic acid esters.
    Notes: Die Thermolyse und Photolyse von 2,3-Dihydro-1,4,2λ5-oxazaphospholen 2, die Photolyse von 1-azetine 3 wie auch die 1,3-Eliminierung von Chlorwasserstoff aus Imidoylchloriden 4 verläuft über die Nitril-ylid-Zwischenstufe 1. Dies wird aus dem jeweils gleichen Produkt-verhältnis der isomeren Cycloaddukte 5:6 bei der Abfangreaktion mit Acrylsäureestern abgeleitet.
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    1,8-Di-tert-butyl-[9-13C]-9-fluorenyl, Bis (2-tert-butylphenyl) [α-13C]methyl und ihre Dimeren (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1903-1914 
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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: 1,8-Di-tert-butyl-[9-13C]-9-fluorenyl, Bis(2-tert-butylphenyl)[α-13C]methyl and their DimersThe preparation of the title compounds is reported. The 1H n. m. r. spectra of the dimers of 1 and [9-13C]-1, respectively, yield the cyclohexadiene structure 12 for the dimer. The 1H n. m. r. spectrum of [α-13C]-2 dimer confirms structure 1411). The e. s. r. results of 1 and 2 are discussed.
    Notes: Die Darstellung der Titelverbindungen wird beschrieben. Die 1H-NMR-Spektren der Dimeren von 1 bzw. [9-13C]- 1 ergeben die Cyclohexadien-Struktur 12 für das Dimere. das 1H-NMR-Spektrum des [α-13C]- 2-Dimeren bestätigt die Struktur 14 11). Die ESR-Ergebnisse (a(H) und a(13C)) von 1 und 2 werden diskutiert.
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    Photochemie kleiner Ringe, 30. Photochemie β, γ-ungesättigter Aldehyde. - Mechanismus der Photofragmentierung phenylsubstituierter Cyclopentencarbaldehyde (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1835-1855 
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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: Photochemistry of Small Rings, 30. Photochemistry of β,γ-Unsaturated Aldehydes.  -  Mechanism of the Photofragmentation of Phenyl-substituted CyclopentenecarbaldehydesA new synthesis of β,γ-unsaturated cyclopentenecarbaldehydes 1 by thermolysis of bicyclo-[3.1.0]hexenols 13 is described. Photolysis of the aldehydes 1 in benzene solution affords the cis-configurated cyclopentenes 2 in good yields. Cyclopentaphenanthrenes 16 are isolated as byproducts. 2 undergoes an electrocyclic reaction to form 17, which is then dehydrogenated to 16. The quantum yields of the photofragmentation and -cyclization are Φ2 = 0.23 and Φ16 = 0.07, respectively. From the emission spectra of 1a the energy of the singlet and triplet state is calculated to ES1 = 84.1 and ET1 = 62.2 kcal/mole. The kinetics of photoreactions 1 → 2 → 16 are studied using ED- and EDQ-diagrams. Sensitization studies demonstrate that the photoreaction 1 → 2 can also occur via a triplet state, but with reduced effectivity. Since quenching with piperylene is ineffective the reaction 1 → 2 very probably involves predominantly an n-π-singlet state. The mechanism proposed for the stereospecific, intramolecular reaction 1 → 2 involves the formation of a formyl allyl radical as a main intermediate.
    Notes: Eine neue Synthese von β,γ-ungesättigten Cyclopentencarbaldehyden 1 durch Thermolyse von Bicyclo [3.1.0]hexenolen 13 wird beschrieben. Die Photolyse der Aldehyde 1 in Benzol ergibt in guten ausbeuten die cis-konfigurierten Cyclopentene 2 und als Nebenprodukte die Cyclopentaphenanthrene 16.2 geht durch elektrocyclischen Ringschluß in 17 über, das unter Dehydrierung in 16 umgewandelt wird. Die Quantenausbeuten der photofragmentierung bzw. -cyclisierung betragen Φ2 = 0.23 bzw. Φ16 = 0.07. aus den Emissionsspektren von 1a wird die Energie von singulett- und Triplett-Zustand zu ES1 = 84.1 bzw. ET1 = 62.2 kcal/mol errechnet. Die Kinetik der Photoreaktionen 1 → 2 → 16 wird mit Hilfe von Ed- und EDQ-Diagrammen näher studiert. Wie Sensibilisierungsstudien zeigen, kann die Photoreaktion 1 → 2, wenn auch mit geringerer Effektivität, über einen Triplett-Zustand verlaufen. Sie läßt sich mit Piperylen nicht löschen, weshalb die Reaktion 1 → 2 weitgehend über einen angeregten n-π-S1-Zustand formuliert wird. Für den Mechanismus der stereospezifischen, intramolekularen (D-Markierung) Reaktion 1 → 2 wird ein Formyl-Allyl-Radikalpaar als Wesentliche Zwischenstufe vorgeschlagen.
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    Photoelektronenspektren und Moleküleigenschaften, XXXIV. Cyanamid (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1882-1890 
    Details
    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 Molecular Properties, XXXIV. CyanamideThe PE spectrum of cyanamide is easily assigned by comparison with that of the isoelectronic acetonitrile. The orbital sequence obtained is supported by vibrational fine structures, by the PE spectrum of dimethylcyanamide, and by CNDO calculations. Furthermore, the calculated charge densities render possible an appreciation of properties of cyanamide and its alkyl derivatives.
    Notes: Das PE-Spektrum von Cyanamid läßt sich durch Vergleich mit dem des isoelektronischen Acetonitrils zwanglos zuordnen. Die so abgeleitete Orbitalreihenfolge wird durch Schwingungsfeinstrukturen, das PE-Spektrum von Dimethylcyanamid sowie durch CNDO-Rechnungen gestützt. Die berechneten Ladungsdichten erlauben darüber hinaus. Eigenschaften von Cyanamid und seinen Alkylderivaten zu verstehen.
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    URL: http://dx.doi.org/10.1002/cber.19741070612
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    Kondensierte Ringsysteme VI. Synthese des [4.2.2]Propella-7,9-diens, eines 1,4-überbrückten Dewar-Benzols (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1915-1924 
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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: Condensed Ring Systems, VI. Synthesis of [4.2.2]Propella-7,9-diene, a Dewar Benzene Bridged in 1,4-PositionThe reaction of 8,11-dithia [4.3.3] propellane (1, n = 4) with N-chlorosuccinimide and monoperphthalic acid yields a mixture of four isomeric dichlorinated disulfones (2, n = 4). The major isomer 7 is formed in 40% yield. Upon treatment of 2 (n = 4) with potassium tert-butoxide at low temperatures [4.2.2] propella-7,9-diene2) (3, n = 4) is obtained. The constitution of 3 (n = 4) is deduced by 1H and 13C n. m. r as well as mass spectrometry.
    Notes: Die Umsetzung des 8,11-Dithia [4.3.3] propellans (1, n = 4) mit N-Chlorsuccinimid und Monoperphthalsäure führt zu einem Gemisch von vier isomeren dichlorierten Disulfonen (2, n = 4), von denen das Hauptprodukt 7 in 40proz. Ausbeute entsteht. 2 (n = 4) läßt sich mit Kalium-tert-butylat bei tiefen Temperaturen in das [4.2.2]Propella-7,9-dien2)(3, n = 4) überführen, dessen Konstitution durch die 1H-, 13C-NMR- und Massenspektren bewiesen wird.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070615
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  • 98
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    Photoisomerisierung in Bicyclo[3.2.2]nona-6,8-dien-Derivaten (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1988-1997 
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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: Photoisomerisation Reactions in Bicyclo[3.2.2]nona-6,8-diene DerivativesFrom the photochemical behavior of suitably substituted derivatives (dicarboxylic ester 3a, dicarboxylic acid 3b, bis(trifluoromethyl)-derivative 3c) it is concluded, that in the bicyclo-[3.2.2]nona-6,8-diene skeleton 1 (n = 3) the [2π + 2π]-Cycloaddition to 2 (n = 3) neither by direct nor by sensitized excitation takes place. Instead 1,3-alkyl shift (3a → 6a) and di-π-methane-rearrangement 3a → 7a, 3c → 8c) are observed. Arguments for this behavior differing from the lower homologues 1 (n = 0, 1, 2) are discussed.
    Notes: Aus dem photochemischen Verhalten geeignet substituierter Derivate (Diester 3a, Dicarbonsäure 3b, Bis-trifluormethyl-Derivat 3c) wird geschlossen, daß im Bicyclo[3.2.2]nona-6,8-dien-Gerüst 1 (n = 3) die [2π + 2π]-Cycloaddition zu 2 (n = 3) weder bei direkter noch bei sensibilisierter Lichtanregung stattfindet. Als Ersatzreaktionen werden 1,3-Alkylverschiebung (3a → 6a) und Di-π-Methanumlagerung (3a → 7a, 3c → 8c) beobachtet. Gründe für dieses von den niedrigeren Homologen 1 (n = 0, 1, 2) abweichende Verhalten werden diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070621
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    PFT-13C-NMR- und Massenspektren von HeterocyclenNMR-Spektroskopische Studien, 3: 1. und 2. Mitteilung: H. Dürr und W. Bujnoch, Liebigs Ann. Chem. 1973, 1691; H. Dürr und H. Kober, Chem. Ber. 106, 1565 (1973).. - 1,2-Diazaspio[4.4]nonatetraene, Azaindolizine und 3aH-Indazole (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2037-2049 
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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: PFT-13C-N.M.R. and Mass Spectra of Heterocycles.  -  1,2-Diazaspiro[4.4]nonatetraenesl Azaindolizines, and 3aH-Indazoles13C n.m.r. spectra obtained by the pulse Fourier transform method of 1,2-diazaspiro[4.4]-nonatetraenes 1, azaindolizines 2, and 3aH-indazoles 3 are described. A combination of highest and lowest field resonances allows an unambigous distinction between 1 and 2. A similiar approach is suggested for 3. Estimated increments from model compounds agree well with the c.m.r. spectra. „Strickspektren“ demonstrate the effect of the substituents on the chemical shift of 1 - 3. The mass spectra of 1 - 3 are discussed briefly.
    Notes: Die mit der Puls-Fourier-Transform-Methode erhaltenen 13C-NMR-Spektren von 1,2- Diazaspiro[4.4]nonatetraenene 1, Azaindolizinen 2 und 3aH-Indazolen 3 werden beschrieben. aus einer Kombination von Höchst-und Tiefstfeld-Resonanzfrequenzen konnten die Strukturen 1 und 2 eindeutig unterschieden werden. Eine entsprechende Analyse wurde für 3 vorgenommen. Inkrementabschätzungen führten zu meist guter Übereinstimmung mit den gemessenen Spektren. Aus den Strichspektren kann der durch die verschiedenen Substituenten hervorgerufene Einfluß auf die chemischen Verschiebung von 1 - 3 werden kurz diskutiert.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19741070626
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  • 100
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    Notiz über die Biogenese von Polyinamiden (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2120-2122 
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    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.19741070633
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