ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Inorganic Chemistry  (29)
  • Ostwald ripening  (4)
  • Neue politische Ökonomie
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    International journal of earth sciences 85 (1996), S. 29-37 
    ISSN: 1437-3262
    Keywords: Banded mineralization ; Harz mountains ; Self-organization ; Iron, manganese, ferrihydrite, birnessite ; Time-series analysis ; Aquatic systems ; Iron bacteria ; Ostwald ripening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract A recent early diagenetic banded iron-manganese mud has been forming underground in a closed lead-zinc mine for approximately 40 years. The processes leading to the banded structure of the precipitate were studied during a period of 2 years. Therefore, 19 physical and chemical parameters were measured regularly in short intervals. The resulting time series were analysed with respect to the data sets of the monthly chemical analyses of the descendent mine water, the daily rainfall and the mineral content. The results reveal that the precipitated material undergoes internal self-organization due to interaction of redox, colloid-chemical, microbial, electrical and ripening processes, and not exclusively produced by seasonal fluctuations of material input. Thus, the primary banding of the material, caused by externally forced fluctuations of the redox conditions within the mine water, is reorganized after a short time. The finally observed bands are controlled by non-linear coupling of reaction and transport processes within the mud. A genetic model for the banded mineralization was developed and verified by numerical simulation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    International journal of earth sciences 85 (1996), S. 19-28 
    ISSN: 1437-3262
    Keywords: Anastomoses ; Crystal zoning ; Snow bands ; Liesegang rings ; Ostwald ripening ; Self organization ; Siderite ; Supersaturation theory ; Zebra rock
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Morphological instabilities in periodic patterns occurring both in precipitation and crystallization processes (Liesegang rings and crystal zoning) are investigated and compared with similar patterns in geological samples (zebra rocks and mud bands in snow sediments). In classical Liesegang systems, undisturbed parallel or concentric precipitation bands are emanated from even or concentric diffusion sources in homogeneous diffusion matrices of gelatine or other gels. In the case of superposing diffusion sources, sources with undulatory curvatures or local diffusion barriers there may occur several types of instabilities within the sequence of regular patterns: (a) gaps within the bands forming radial alleys free of precipitate, (b) transition from broken bands to speckled patterns and (c) apparent branching of bands linked together by so-called anastomoses. Calculations with a competitive particle growth (CPG) model show that lateral instabilities in Liesegang bands (gaps and radial alleys of gaps) are the result of Ostwald ripening effects taking place after precipitation. Apparent branching of bands or formation of anastomoses can be simulated with a prenucleation model according to Ostwald's supersaturation theory. Similar irregularities can be observed in zebra rocks (e.g. banded siderite) whose bandings are commonly explained by sequential sedimentation processes. A very different mechanism is assumed to be responsible for the origin of mud bands in snow sediments. An initially homogeneous distribution of intrinsic mud in snow sediments can be arranged into parallel bands according to a crystal zoning mechanism which is based on repeated thawing and freezing of the snow sediment due to the daily alternation of sun and darkness.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Geologische Rundschau 85 (1996), S. 29-37 
    ISSN: 0016-7835
    Keywords: Key words Banded mineralization ; Harz mountains ; Self-organization ; Iron ; manganese ; ferrihydrite ; birnessite ; Time-series analysis ; Aquatic systems ; Iron bacteria ; Ostwald ripening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  A recent early diagenetic banded iron–manganese mud has been forming underground in a closed lead–zinc mine for approximately 40 years. The processes leading to the banded structure of the precipitate were studied during a period of 2 years. Therefore, 19 physical and chemical parameters were measured regularly in short intervals. The resulting time series were analysed with respect to the data sets of the monthly chemical analyses of the descendent mine water, the daily rainfall and the mineral content. The results reveal that the precipitated material undergoes internal self-organization due to interaction of redox, colloid-chemical, microbial, electrical and ripening processes, and not exclusively produced by seasonal fluctuations of material input. Thus, the primary banding of the material, caused by externally forced fluctuations of the redox conditions within the mine water, is reorganized after a short time. The finally observed bands are controlled by non-linear coupling of reaction and transport processes within the mud. A genetic model for the banded mineralization was developed and verified by numerical simulation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Geologische Rundschau 85 (1996), S. 19-28 
    ISSN: 0016-7835
    Keywords: Key words Anastomoses ; Crystal zoning ; Snow bands ; Liesegang rings ; Ostwald ripening ; Self organization ; Siderite ; Supersaturation theory ; Zebra rock
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Morphological instabilities in periodic patterns occurring both in precipitation and crystallization processes (Liesegang rings and crystal zoning) are investigated and compared with similar patterns in geological samples (zebra rocks and mud bands in snow sediments). In classical Liesegang systems, undisturbed parallel or concentric precipitation bands are emanated from even or concentric diffusion sources in homogeneous diffusion matrices of gelatine or other gels. In the case of superposing diffusion sources, sources with undulatory curvatures or local diffusion barriers there may occur several types of instabilities within the sequence of regular patterns: (a) gaps within the bands forming radial alleys free of precipitate, (b) transition from broken bands to speckled patterns and (c) apparent branching of bands linked together by so-called anastomoses. Calculations with a competitive particle growth (CPG) model show that lateral instabilities in Liesegang bands (gaps and radial alleys of gaps) are the result of Ostwald ripening effects taking place after precipitation. Apparent branching of bands or formation of anastomoses can be simulated with a prenucleation model according to Ostwald's supersaturation theory. Similar irregularities can be observed in zebra rocks (e.g. banded siderite) whose bandings are commonly explained by sequential sedimentation processes. A very different mechanism is assumed to be responsible for the origin of mud bands in snow sediments. An initially homogeneous distribution of intrinsic mud in snow sediments can be arranged into parallel bands according to a crystal zoning mechanism which is based on repeated thawing and freezing of the snow sediment due to the daily alternation of sun and darkness.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 581 (1990), S. 33-40 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About Tribenzyltin- and TribenzyltitaniumcyclopentadienylThe organocerium(III) compound Na(THF)[(π-C5H5)3Ce(σ-C5H5)] (I) reacts with (C6H5CH2)3SnCl and (C6H5CH2)3TiCl after a SN-reaction under separation of Nacl and (C5H5)3Ce to tribenzyltin- resp.-titaniumcyclopentadienyl (C6H5CH2)3MC5H5 [M = Sn, (II); Ti, (III)]. A special characterization of II and III was carried out by their elementary analysis, I.R. spectroscopy and 1H, 13C, and 119Sn N.M.R. spectroscopy. These results allow the statement that II and III are better to be described by the formulae (C6H5CH2)3Sn(σ-C5H5) and (C6H5CH2)3Ti(π-C5H5), respectively.
    Notes: Die Organocer(III)-Verbindung Na(THF)[(π-C5H5)3Ce(σ-C5H5)] (I) reagiert mit (C6H5CH2)3SnCl und (C6H5CH2)3TiCl im Sinne einer SN-Reaktion unter Abscheidung von NaCl und (C5H5)3Ce zu Tribenzylzinn- bzw. -titancyclopentadienyl (C6H5CH2)3MC5H5 [M = Sn, (II); Ti, (III)]. Eine eingehende Charakterisierung von II und III erfolgte durch Elementaranalysen, IR-Spektroskopie sowie durch 1H-, 13C- bzw. 119Sn-NMR-spektroskopische Untersuchungen. Diesbezügliche Resultate gestatten die Aussage, daßII bzw. III durch die Formeln (C6H5CH2)3Sn(σ-C5H5) und (C6H5CH2)3Ti(π-C5H5) zu beschreiben sind.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1957-1961 
    ISSN: 0044-2313
    Keywords: Organolanthanide chemistry, samarium, yttrium ; 2-(dimethylaminomethyl)ferrocenyl compounds ; heterobimetallic organolanthanide chelate complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contribution to Organolanthanoide Chemistry. III. On 2-(Dimethylaminomethyl)ferrocenyl Compounds of Samarium and YttriumEarlier results, indicating the ability of the bulky 2-(dimethylaminomethyl)ferrocenyl-group (FcN) to form thermocally stable, heterobimetallic organolanthanide compounds, were proved by the synthesis of organo-rare-earth derivatives (C5Me5)2Sm(FcN) (II), (C5H5)Sm(FcN)Cl (III), respectively (C5Me5)Y(FcN)Cl (IV) from the corresponding complex cyclopentadienyl rare-earth chlorides (C5Me5)2SmCl · KCl · THF, (C5H5)SmCl2 · THF and (C5Me5)YCl2 · KCl · 1,8 THF and 2-(dimethylaminomethyl)ferrocenyl lithium (FcN)Li (I) as organylating agent. The synthesized compounds were proved by elementary analysis, IR, 1H, 13C NMR and UV-VIS spectra as well as by measuring the magnetic moments and by mass spectroscopy.
    Notes: Frühere Befunde, wonach die voluminöse 2-(Dimethylaminomethyl)ferrocenyl-Gruppierung (FcN) zur Bildung thermisch stabiler, heterobimetallischer Organolanthanoid(III)-Verbindungen befähigt ist, wurden durch die Darstellung der Organoseltenerd(III)-Derivate (C5Me5)2Sm(FcN) (II), (C5H5)Sm(FcN)Cl (III) und (C5Me5)Y(FcN)Cl (IV) aus den betreffenden komplexen Cyclopentadienyl-Seltenerd(III)-chloriden (C5Me5)2SmCl · KCl · THF, (C5H5)SmCl2 · THF bzw. (C5Me5)YCl2 · KCl · 1,8 THF und 2-(Dimethylaminomethyl)ferrocenyl-Lithium (FcN)Li (I) als Organylierungsmittel bestätigt. Die erhaltenen Verbindungen wurden durch Elementaranalysen, IR-, 1H-NMR-, 13C-NMR- und UV-VIS-Spektren sowie durch die Ermittlung der effektiven magnetischen Momente und die Aufnahme der Massenspektren charakterisiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0044-2313
    Keywords: 2-(Dimethylaminomethyl)ferrocenyl 3 d metal compounds ; preparation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Transition Metal Alkyl Compounds. 57. 2-(Dimethylaminomethyl)ferrocenyl Compounds of 3 d Elements[2-(Dimethylaminomethyl)ferrocenyl]lithium, (FcN)Li (I), reacts with MCl2 · xTHF to (FcN)2Mn (II), (FcN)2Co (III), Li2[Fe(FcN)2Cl2] (IV) as well as with FeCl3 to (FcN)3Fe (V). In the same way the complex (C5H5)2V(FcN) (VI) was obtained from (C5H5)2VCl. When I is reacted with M(acac)3 (M = Cr, Co) only a partial ligand exchange took place  -  independently from the molar ratio of the reactants  -  with formation of (FcN)Cr(acac)2 (VII) and (FcN)Co(acac) (VIII).An intensive characterization of II-VIII was achieved by elementary analysis, determination of molecular weights, IR-, UV-VIS- and 1H-NMR spectra as well as determination of effective magnetic moments.
    Notes: [2-(Dimethylaminomethyl)ferrocenyl]lithium, (FcN)Li (I), reagiert mit MCl2 · xTHF zu (FcN)2Mn (II), (FcN)2Co (III), Li2[Fe(FcN)2Cl2] (IV) sowie mit FeCl3 zu (FcN)3Fe (V). Auf gleiche Weise wurde aus (C5H5)2 VCl der Komplex (C5H5)2V(FcN) (VI) erhalten. Bei der Einwirkung von I auf M(acac)3 (M = Cr, Co) erfolgte unabhängig vom Molverhältnis der Reaktanten nur ein partieller Ligandenaustausch unter Bildung von (FcN)Cr(acac)2 (VII) und (FcN)Co(acac) (VIII).Eine eingehende Charakterisierung von II-VIII erfolgte durch Elementaranalysen, Molmassebestimmungen, IR-, UV-VIS- und 1H-NMR-Spektren sowie Bestimmung der effektiven magnetischen Momente.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 564 (1988), S. 81-84 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Organo Transition Metal Compounds. 53. Synthesis and Properties of Manganese Tetravinyloxide, Mn(OCH=CH2)4 · 0.5 THFTetrakis(1-Norbornyl)manganese (I) reacts with boiling tetrahydrofuran forming ethylene, norbornane, and manganese tetravinyloxide Mn(OCH=CH2)4 · 0.5 THF (II) as the first manganese tetraalcoxide. The compound was characterized by elementary analysis, the i.r. and 1H n.m.r. spectrum, the effective magnetic moment, and the protolysis products.
    Notes: Tetrakis(1-norbornyl)mangan (I) reagiert mit siedendem Tetrahydrofuran unter Abspaltung von Ethylen und Norbornan zu Mangantetravinyloxid, Mn(OCH=CH2)4 · 0,5 THF (II), als dem ersten bekannt gewordenen Mangan(IV)-alkoxid. Die Verbindung wurde durch Elementaranalyse, das IR- und 1H-NMR-Spektrum, das effektive magnetische Moment und durch die Protolyseprodukte charakterisiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1489-1493 
    ISSN: 0044-2313
    Keywords: Organotransition metal chemistry ; heterobimetallic 2-(dimethylaminomethyl)ferrocenyl derivatives of vanadium, niobium, tantalum ; synthesis ; 1H-n.m.r.-, uv-vis spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On 2-(Dimethylaminomethyl)ferrocenyl Compounds of Vanadium, Niobium, and TantalumFormer results, indicating the ability of (dimethylaminomethyl)ferrocenyl groups forming stable σ-organo transition-metal derivatives, were proved by the synthesis of heterobimetallic 2-(dimethylaminomethyl)ferrocenyl compounds of the three-valued vanadium as well as five valued niobium and tantalum from VCl3, NbCl5, TaCl5, and (FcN)Li (I).The synthesis and properties of the compounds (FcN)2VCl (II), (FcN)nNbCl5-n(THF)x [n = 1, x = 1,3 (III); n = 2, x = 0 (IV); n = 3, x = 0 (V)] as well as (FcN)TaCl4(THF)1.5 (VI) are reported. An intensive characterization, especially in respect of possible chelate structures was tried by i.r., 1H-n.m.r., uv-vis, mass spectroscopy, and elementary analysis.
    Notes: Frühere Befunde, wonach (Dimethylaminomethyl)-ferrocenyl-Gruppen (FcN) zur Bildung stabiler σ-Organoübergangsmetall-Derivate befähigt sind, wurden durch die Synthese heterobimetallischer 2-(Dimethylaminomethyl)-ferrocenyl-Verbindungen des dreiwertigen Vanadiums sowie des fünfwertigen Niobs und Tantals aus den Metallchloriden VCl3, MCl5 (M = Nb, Ta) und (FcN)Li (I) bestätigt. Die Darstellung und die Eigenschaften der Verbindungen (FcN)2VCl (II), (FcN)nNbCl5-n(THF)x [n = 1, x = 1,3 (III); n = 2, x = 0 (IV); n = 3, x = 0 (V)] sowie von (FcN)TaCl4 · 1,5 THF (VI) werden mitgeteilt. Eine eingehende Charakterisierung, insbesondere hinsichtlich der Ausbildung möglicher Chelatstrukturen, erfolgte durch IR-, 1H-NMR-, UV-VIS- und Massenspektroskopie sowie durch Elementaranalysen.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen 51. Darstellung und Charakterisierung der Organomangan (III)- Verbindung Na[Mn(C5H5)4]Bei der Reaktion von Mn(acac)3 mit NaC5H5 in Tetrahydrofuran entsteht kristallines, rotviolettes, diamagnetisches Na[Mn(η1-C5H5)4-n(η5 -C5H5)n]. Eine nähere Charakterisierung erfolgte durch das 1H-NMR-, IR- und UV-VIS-Spektrum sowie durch Leitfähigkeitsmessngen.
    Notes: At reaction of Mn(acac)3 with NaC5H5 in tetrahydrofuran solution Na[Mn(η1-C5H5)4-n(η5 -C5H5)n] was obtained as a crystalline, red-violet, diamagnetic organomanganese(III) compound, which was characterized by n.m.r., i.r., and electronic spectra and by conductivity measurements.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...