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  • 1
    Electronic Resource
    Electronic Resource
    The radiation of spring snails of the genus Belgrandiella in Austria (Mollusca: Caenogastropoda: Hydrobiidae) (1996)
    Springer
    Hydrobiologia 319 (1996), S. 119-129 
    Details
    ISSN: 1573-5117
    Keywords: Austria ; Belgrandiella ; crenobionts ; endemism ; Hydrobiidae ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study introduces two new species, Belgrandiella mimula and B. wawrai. The anatomy of B. parreyssii is described for the first time. ‘Graziana’ austriana is placed in the genus Belgrandiella. This increases the number of Austrian Belgrandiella species to seven. A cladistic analysis demonstrates that this East Alpine radiation is well defined by anatomy and probably deserves taxonomic separation. The subdivision of the Austrian species of Belgrandiella into two groups is consistent with biogeography. All seven species are extreme endemics and highly endangered, as each is found only in a single spring or a single, isolated valley.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00016880
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  • 2
    Electronic Resource
    Electronic Resource
    Radiation of crenobiontic gastropods on an ancient continental island: the Hemistomia-clade in New Caledonia (Gastropoda: Hydrobiidae) (1998)
    Springer
    Hydrobiologia 367 (1998), S. 43-129 
    Details
    ISSN: 1573-5117
    Keywords: anatomy ; conservation ; endemism ; paraphyly ; spring snails ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A vast radiation of hydrobiid spring snails endemic to New Caledonia, a continental island in the Southwest Pacific known for its unique flora and fauna, is described. This radiation comprises a total of 54 named species of which 50 are new. The majority of the species belong to the most basal genus, Hemistomia, which happens to be the first one described from New Caledonia. The remaining species are attributed to four genera, Kanakyella, Pidaconomus, Caledoconcha, and Leiorhagium, which are all introduced in this paper. The radiation as a whole is characterized by the formation of the digestive gland, the stomach with an additional, ciliated proximal chamber, and the subdivision of the pallial oviduct. Whether or not a denticle situated behind the outer lip is a synapomorphy of the whole group cannot be stated with certainty. The genera are distinguished mainly by features of the genital system. For the cladistic analysis, which resulted in 419 equally parsimonious trees, only five characters could be used, and even those were not free of homoplasy. The genera Hemistomia and Pidaconomus are paraphyletic according to this analysis. In contrast to the widely accepted principles of phylogenetic systematics we retain these paraphyletic genera, because otherwise the diversification, i.e. the evolution, which has taken place within the clade could not be expressed in the classification. The majority of the species occur in very restricted areas. Twenty-six (48%) species were found in a single locality and only six species (11%) in ten or more places. The hydrobiid diversity of west coast drainages is much higher than that of river systems draining to the east. This is, at least partly, explained by the differing precipitation regimes and geological conditions of the regions considered. The west coast receives much less rainfall so that in continuous periods of drought the area of a species would be fragmented by drying up of springs and consequently gene flow between the remaining populations reduced, enhancing speciation. In addition, the west is geologically more heterogenous. Unfavourable, insular ultramafic mountains represent barriers for the dispersal along the west coast. Many of the taxa are highly threatened to become extinct in the closer future as a consequence of human activities, such as deforestation, agriculture, surface mining, or uncontrolled fires. The conservation of the unique New Caledonian radiation of crenobiontic gastropods requires a transformation of land management practices on privately-owned sites, and a more global reappraisal of the impact of fire and deforestation on water resources.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003219931171
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  • 3
    Electronic Resource
    Electronic Resource
    Cyclisierung von (Fluorsilyl)phosphanen zu 1,3-Diphospha-2,4-disilacyclobutanen - Kristallstrukturuntersuchungen (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 146-151 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclisation of (Fluorsilyl)phosphanes to 1,3-Diphospha-2,4-disilacyclobutanes - Crystal Structure DeterminationsLithiated tert-butylphosphane reacts with di-tert-butyldifluorosilane and with difluorobis[methyl(trimethylsilyl)amino]silane to give the (fluorosilyl)phosphanes 1 and 2 as well as the (di-tert-butylsilanediyl)bisphosphane 3. The cyclic compounds 4 and 5 are obtained in the reaction of 1 and 2 with tert-C4H9Li. Dilithiated 3 reacts with dichlorophenylphosphane to form the 1,2,3-triphospha-4-silacyclobutane 6. According to crystal structure analyses, 4 and 5 contain planar Si2P2 rings with Si—P bonds between 224.1(1) and 228.0(1) pm.
    Notes: Lithiiertes tert-Butylphosphan reagiert mit Di-tert-butyldifluorsilan und Difluorbis[methyl(trimethylsilyl)amino]silan zu den (Fluorsilyl)phosphanen 1 und 2 sowie zum (Di-tert-butylsilandiyl)-bisphosphan 3. Die cyclischen Verbindungen 4 und 5 werden durch die Umsetzung von 1 und 2 mit tert-C4H9Li erhalten. Dilithiiertes 3 reagiert mit Dichlorphenylphosphan zum 1,2,3-Triphospha-4-silacyclobutan 6. Nach Kristallstrukturanalysen besitzen 4 und 5 jeweils planare Si2P2-Ringe mit Si—P-Bindungen zwischen 224.1(1) und 228.0(1) pm.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160117
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  • 4
    Electronic Resource
    Electronic Resource
    Zur Existenz eines Silaolefins: Synthese und Kristallstrukturen von Wittig- und Diels-Alder-Produkten in Reaktionen lithiierter fluorsilylfunktioneller Diazasilacyclopentene mit Benzaldehyd und Methacrolein (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 282-289 
    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 Existence of a Silaolefin: Synthesis and Crystal Structures of Wittig and Diels-Alder Products in Reactions of Lithiated (Fluorosilyl)diazasilacyclopentenes with Benzaldehyde and MethacroleinLithium salts of 1,2-diaza-3-sila-5-cyclopentenes react with fluorosilanes and aminofluorosilanes to give 4-(fluorosilyl)-substituted compounds 1 - 4. By reaction with tert-butyllithium 1 - 4 themselves form lithium salts 5 - 8, which react with fluorosilanes in a second substitution giving 9 and 10.5 and 7 undergo a Wittig-type reaction with benzaldehyde to form the benzylidene derivative 11. Spirocyclic Diels-Alder adducts (12, 13) are obtained from the reaction of 5 and 6 with 2-methyl-2-propenal. The propenylidene derivative 14 is formed as a by product. With excess 2-methyl-2-propenal, 12 reacts as a dienophile giving the oligocyclic Diels-Alder adducts 15 and 16. The crystal structures of 11 and 15 are reported.
    Notes: Lithiumsalze der 1,2-Diaza-3-sila-5-cyclopentene reagieren mit Fluorsilanen und Aminofluorsilanen zu den 4-(Fluorsilyl)-substituierten Verbindungen 1 - 4. In Reaktion mit tert-Butyllithium bilden 1 - 4 erneut Lithiumsalze (5 - 8), die mit Fluorsilanen unter Zweitsubstitution zu 9 und 10 reagieren. In Wittig-analoger Reaktion reagieren 5 und 7 mit Benzaldehyd zum Benzyliden-Derivat 11. Spirocyclische Diels-Alder-Addukte (12, 13) werden aus 5 und 6 mit 2-Methyl-2-propenal erhalten. Als Nebenprodukt entsteht das Propenyliden-Derivat 14. Mit überschüssigem Dien (2-Methyl-2-propenal) reagiert 12 als Dienophil zu den oligocyclischen Diels-Alder-Addukten 15 und 16. Kristallstrukturen von 11 und 15 werden mitgeteilt.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160132
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  • 5
    Electronic Resource
    Electronic Resource
    Synthese cyclischer Silylhydrazine - Kristallstruktur eines fünfgliedrigen Kreuz-Dimeren (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 290-298 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Cyclic Silylhydrazines - Crystal Structure of a Five-membered Cross Dimerisation ProductN,N-Bis(fluorosilyl)amines (1 - 3) react with dilithiated hydrazines to give four- and five-membered silylhydrazine rings (4 - 8). The isomerisation of a 3-(tert-butylamino)-1,3-diaza-2,4-disilacyclobutane (8) to a 1,2,4-triaza-3,5-disilacyclopentane (9) has been demonstrated. Lithium salts of silylhydrazines react with fluorosilanes to give substitution products (10 - 15). Dilithiated hydrazine reacts with Me2SiF2 yielding N(SiFMe2)3 (16). The formation of isomeric N-(fluorosilyl)-N,N′-bis(trimethylsilyl)- and N′-(fluorosilyl)-N,N-bis(trimethylsilyl)hydrazines has been accomplished via ring-closure reactions (17 - 19) and confirmed by the crystal structure determination of a five-membered ring cross dimer (19). The ten-membered bicyclic ring system (22) is obtained by the reaction of (14) with dilithiated hydrazine.
    Notes: N,N-Bis(fluorsilyl)amine (1 - 3) reagieren mit dilithiierten Hydrazinen zu vier- und fünfgliedrigen Silylhydrazinringen (4 - 8). Präparativ gelang der Nachweis der Isomerisierung eines 3-(tert-Butylamino)-1,3-diaza-2,4-disilacyclobutans (8) zum 1,2,4-Triaza-3,5-disilacyclopentan (9). Lithiumsalze von Silylhydrazinen reagieren mit Fluorsilanen unter Substitution (10 - 15). Dilithiiertes Hydrazin reagiert mit Me2SiF2 zu N(SiFMe2)3 (16). Die Bildung von isomeren N-(Fluorsilyl)-N,N′-bis(trimethylsilyl)- und N′-Fluorsilyl-N,N-bis(trimethylsilyl)hydrazinen wird durch Ringschlußreaktionen (17 - 19) nachgewiesen und durch die Kristallstrukturuntersuchung eines Kreuz-Dimeren-Fünfrings belegt (19). Der zehngliedrige Bicyclus 22 entsteht in der Reaktion des N,N′-Bis(fluordimethylsilyl)-N,N′-bis(trimethylsilyl)hydrazins(14) mit dilithiiertem Hydrazin.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160133
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  • 6
    Electronic Resource
    Electronic Resource
    Stufenweise Synthese ketten- und ringförmiger Siloxane  -  Kristallstrukturen (1984)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2988-2997 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stepwise Synthesis of Chain and Ring Siloxanes  -  Crystal StructuresDisilanols of the type R2Si(OH)2 (1, 2: R = CHMe2, CMe3) and the fluorosilanol (Me3 C)2Si(OH)F (3) serve as starting materials in the reaction with halosilanes for the stepwise construction of chain siloxanes (4 - 15, 16 - 20). Even siloxanes with bulky tert-butyl or silylamino groups are easily prepared (10, 16, 17, 20). Crystalline silanediols (2, 14, 19) are connected in chains (19) or dimeric rings (2, 14) by hydrogen bonding. The 1,3-difluoro- (18), 1,3-dihydroxy- (19), and 1-fluoro-3-hydroxydisiloxane 6 as well as the cyclotrisiloxane 21 were isolated from the reaction of F2Si(CHMe2)2 with potassium hydroxide. Directed synthesis of Si  -  O six-membered rings (21 - 24) is possible via reaction of 1,3-dihydroxydisiloxanes 19, 20 with di- and trihalosilanes. The crystal structures of 2, 14, and 24 are discussed.
    Notes: Disilanole des Typs R2Si(OH)2 (1, 2: R = CHMe2, CMe3) und das Fluorsilanol (Me3C)2Si(OH)F (3) dienen in Reaktionen mit Halogensilanen als Startmaterial zum stufenweisen Aufbau von kettenförmigen Siloxanen (4 - 15, 16 -20). Auch Siloxane mit voluminösen tert-Butyl- oder Silylaminogruppen sind leicht zugänglich (10, 16, 17, 20). Kristalline Silandiole (2, 14, 19) sind über Wasserstoff-Brückenbindungen ketten- (19) oder dimer-ringförmig (2, 14) verknüpft. Aus der Reaktion von F2Si(CHMe2)2 mit Kaliumhydroxid wurde das 1,3-Difluor- (18), 1,3-Dihydroxy (19), 1-Fluor-3-hydroxydisiloxan 6 sowie da Cyclotrisiloxan 21 isoliert. Die Si  -  O-Sechsringe 21 - 24 können gezielt aus den 1,3-Dihydroxydisiloxanen 19, 20 mit Di- und Trihalogensilanen erhalten werden. Die Kristallstrukturen von 2, 14 und 24 werden diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19841170916
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  • 7
    Electronic Resource
    Electronic Resource
    Stabilisierung und Reaktionen von Iminoboranen  -  Kristallstruktur von (tert-Butylimino)[tris(trimethylsilyl)-silyl]boran (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1117-1126 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stabilisation and Reactions of Iminoboranes - Crystal Structure of (tert-Butylimino)[tris(trimethylsilyl)silyl]boraneThe lithium salts of tris(trimethylsilyl)methane (1) and -silane (2) react with aminohalogenoboranes to give the substitution compounds 3-13. Chloro[tris(trimethylsilyl)methyl](2,2,6,6-tetramethylpiperidino)borane (12) is isolated as THF adduct In contrast to methyl-, ethyl- and isopropyl(trimethylsilyl)amino compounds (3-7) the bis(trimethylsilyl)-(8, 9) and the tert-butyl(trimethylsilyl)amino compounds (10, 11) thermally loose fluorotrimethylsilane with formation of stable iminoboranes (14-17). - 18 is obtained by methanol addition to 14, 19 and 20 by mesitylamine addition to 16 and 17, respectively. The hydrolysis of 14 leads to the formation of the amino(trisilylmethyl)boranol (Me3Si)3C—B(OH)-NHSiMe3 (21). The second product of hydrolysis of 14 (22) is obtained by atmospheric moisture from 21. 22 does not condense to the boroxine in an anhydrous medium. The crystal structure of 17 shows the shortest boron-nitrogen bond length found so far.
    Notes: Die Lithiumsalze des Tris(trimethylsilyl)methans (1) und -silans (2) reagieren mit Aminohalogenboranen zu den Substitutionsverbindungen 3-13. Chlor[tris(trimethylsilyl)-methyl](2,2,6,6-tetramethylpiperidino)boran (12) wird als THF-Addukt isoliert. Im Gegensatz zu den Methyl-, Ethyl- und Isopropyl(trimethylsilyl)amino-Verbindungen (3-7) verlieren Bis(trimethylsilyl)- (8, 9) und die tert-Butyl(trimethylsilyl)amino-Verbindungen (10, 11) thermisch Fluortrimethylsilan unter Bildung stabiler Iminoborane (14-17). - 18 wird durch Methanoladdition an 14 gebildet, 19 und 20 entstehen durch Addition von Mesitylamin an 16 und 17. Die Hydrolyse von 14 führt zur Bildung des Amino(trisilylmethyl)-boranols (Me3Si)3C—B(OH)-NHSiMe3 (21). Das zweite Hydrolyseprodukt von 14 (22) entsteht durch die Einwirkung von Luftfeuchtigkeit auf 21. 22 kondensiert im wasserfreien Medium nicht zum Boroxin. Die Kristallstruktur von 17 zeigt die bislang kürzeste gefundene Bor-Stickstoff-Bindungslänge.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190403
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  • 8
    Electronic Resource
    Electronic Resource
    Synthese eines stabilen Aminosilanols und eines Lithium-Aminosilanolats mit CubanstrukturDiese Arbeit wurde vom Fonds der Chemischen Industrie unterstützt. (1984)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 96 (1984), S. 904-905 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19840961122
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  • 9
    Electronic Resource
    Electronic Resource
    Einfache Synthese stabiler IminoboraneDiese Arbeit wurde von der Deutschen Forschungsgemeinschaft und dem Fonds der Chemischen Industrie unterstützt. (1985)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 97 (1985), S. 335-336 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19850970425
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  • 10
    Electronic Resource
    Electronic Resource
    Ein spirocyclisches DiphosphiranDiese Arbeit wurde von der Deutschen Forschungsgemeinschaft und dem Fonds der Chemischen Industrie unterstützt. (1982)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 94 (1982), S. 461-462 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract.Das vollständige Manuskript dieser Zuschrift erscheint in: Angew. Chem. Suppl. 1982, 1009-1015
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19820940626
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