ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
  • Ostwald ripening  (4)
  • Harz mountains  (2)
  • 2-(Dimethylaminomethyl)ferrocenyl  (1)
  • Springer  (5)
Collection
Keywords
Publisher
  • Springer  (5)
Years
  • 1
    Electronic Resource
    Electronic Resource
    Heterobimetallische Vanadium- und Thallium-2-(dimethylaminomethyl)ferrocenyl-Verbindungen (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 337-351 
    Details
    ISSN: 1434-4475
    Keywords: Vanadium ; Thallium ; Heterobimetallic ; 2-(Dimethylaminomethyl)ferrocenyl ; Orthometallation ; Electron transfer ; Möβbauer spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary Syntheses and properties of 2-(dimethylaminomethyl)ferrocenylderivatives of the composition (FcN) n VCl3−n (FcN=2-(dimethylaminomethyl)ferrocenyl;n=1 (1), 2 (2), 3 (3)), which are formed from VCl3·3THF and (FcN) Li (I), are reported. WhereasCp 2VCl2 (Cp=C5H5) reacts withI under formation ofCp 2V(FcN) (4), VO(acac)2 (acac=anion of acetylacetonate, C5H7O2) can be transformed into the 2-(dimethylaminomethyl)-ferrocenyl compound of tetravalent vanadium (FcN)VO(acac),5). However, when VOCl2·2THF reacts withI, the organovanadium(III)-derivative Li[(FcN)2V(O)Cl] (6) is formed. Reactions of VCl4·2THF,Cp 2VCl2, VOCl3, andCpVOCl2 with (FcN)3Tl (II) lead to thermally instable vanadiumorganic compounds under formation of (FcN)2TlCl (7). A detailed characterization of1–7 was carried out by elementary analysis, determination of effective magnetic moments, IR, mass and1H NMR spectroscopy as well as — especially referring to the formation of possible chelate structures — by UV/Vis andMöβbauer spectroscopy.
    Notes: Zusammenfassung Synthesen und Eigenschaften von 2-(Dimethylaminomethyl)ferrocenyl-Derivaten der Formel (FcN) n VCl3−n (FcN=2-(Dimethylaminomethyl)ferrocenyl;n=1 (1), 2 (2), 3 (3)), die aus VCl3·3THF und (FcN) Li (I) entstehen, werden mitgeteilt. WährendCp 2VCl2 (Cp=C5H5) mitI unter Bildung vonCp 2 V(FcN) (4) reagiert, läßt sich VO (acac)2 (acac=Anion des Acetylacetonates, C5H7O2) in die 2-(Dimethylaminomethyl)ferrocenyl-Verbindung des vierwertigen Vanadiums (FcN)VO(acac),5) überführen. Dagegen entsteht bei Umsetzungen von VOCl2·2THF mitI das Organovanadium (III)-Derivat Li [(FcN)2V(O)Cl] (6). Reaktionen von VCl4·2THF,Cp 2VCl2, VOCl3 undCpVOCl2 mit (FcN)3Tl (II) führen unter Bildung von (FcN)2TlCl (7) zu thermisch instabilen vanadiumorganischen Verbindungen. Eine eingehende Charakterisierung von1–7 erfolgte durch Elementaranalysen, Ermittlung der effektiven magnetischen Momente, IR-, Massen- und NMR-Spektroskopie sowie, insbesondere hinsichtlich der Ausbildung möglicher Chelatstrukturen, durch UV/Vis und Mößbauer-Spektroskopie.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Self-organization of recent rhythmic iron-manganese precipitations in underground mines in the Harz mountains (1996)
    Springer
    International journal of earth sciences 85 (1996), S. 29-37 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00192057
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Morphological instabilities in pattern formation by precipitation and crystallization processes (1996)
    Springer
    International journal of earth sciences 85 (1996), S. 19-28 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00192056
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Self-organization of recent rhythmic iron–manganese precipitations in underground mines in the Harz mountains (1996)
    Springer
    Geologische Rundschau 85 (1996), S. 29-37 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00192057
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Morphological instabilities in pattern formation by precipitation and crystallization processes (1996)
    Springer
    Geologische Rundschau 85 (1996), S. 19-28 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00192056
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...