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  • 11
    Electronic Resource
    Electronic Resource
    Hetero-π-Systeme, 9. Über die Beziehungen zwischen Silaethenen und Methylsilylenen (1984)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2369-2381 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hetero-π-Systems, 9. About the Relationships between Silaethenes and MethylsilylenesSilaethenes 1 and the isomeric methylsilylenes 2 are separately existing species, but can readily be interconverted in an argon matrix via a photochemically induced 1,2-H shift. In case of the thermal excitation in the gas phase examples for both directions have been detected spectroscopically: the isomerisation of a silaolefin into the corresponding silylene (1d → 2d) and the formation of a silene from a silylene (2f → 1f).
    Notes: Die Silaolefine 1 und dazu isomeren Methylsilylene 2 sind getrennt existenzfähige Spezies, lassen sich in einer Argonmatrix aber über eine photochemisch induzierte 1,2-H-Wanderung leicht ineinander umwandeln. Bei thermischer Anregung in der Gasphase ist sowohl die Isomerisierung eines Silaolefins zum zugehörigen Silylen (1d → 2d) als auch eines Silylens zum entsprechenden Silen (2f → 1f) direkt spektroskopisch nachweisbar.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19841170709
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  • 12
    Electronic Resource
    Electronic Resource
    Kleine Ringe, 37: Weitere Versuche zur Matrixisolierung von Tetramethyltetrahedran (1981)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 3959-3964 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Small Rings, 37: Further Attempts on Matrix Isolation of TetramethyltetrahedraneIrradiation of diketone 4 or cyclobutenedicarboxylic anhydride 6 in an argon matrix leads to tetramethylcyclopentadienone (5). On the contrary, the valence isomeric anhydride 7 gives cyclobutadiene 3 via lactone 8 which also can be prepared directly from α-pyrone 10. Tetramethyltetrahedrane (2) cannot be detected.
    Notes: Belichtung von Diketon 4 oder Cyclobutendicarbonsäureanhydrid 6 in einer Argonmatrix führt zu Tetramethylcyclopentadienon (5). Im Gegensatz dazu liefert das zu 6 valenzisomere Anhydrid 7 über das bicyclische Lacton 8, welches auch direkt aus dem α-Pyron 10 zugänglich ist, das Cyclobutadien 3. Tetramethyltetrahedran (2) ist nicht nachweisbar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19811141217
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  • 13
    Electronic Resource
    Electronic Resource
    Kleine Ringe, 36: Versuche zur Darstellung von Tetramethyltetrahedran aus alicyclischen Vorstufen (1981)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 3935-3958 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Small Rings, 36: Attempts to Synthesize Tetramethyltetrahedrane from Alicyclic PrecursorsSynthesis as well as the thermal and photochemical behaviour of compounds with ring skeletons 1 and 3 are described. Whereas the former are accessible by standard procedures the approach to the bicyclobutane derivatives is based on the isomerization of diester 1b into valence isomer 3b which can be achieved in good yield by SiO2, or Al2O3. There are only minor differences in the cleavage of the pairs 1/3 provoked by heating or photochemical excitation. This is even true for irradiations in argon at 10 K. Under those conditions anhydrides la and 3a form the same charge transfer complex 28a between tetramethylcyclobutadiene and phthalic anhydride. A direct detection of tetramethyltetrahedrane using these means is not possible.
    Notes: Synthese sowie thermisches und photochemisches Verhalten von Verbindungen mit den Ringgerüsten 1 bzw. 3 werden beschrieben. Während erstere nach Standardverfahren zugänglich sind, fußt der präparative Zugang der Bicyclobutan-Derivate auf der mit SiO2 oder Al2O3 in guter Ausbeute erreichbaren Isomerisierung von Diester 1b zum Valenzisomeren 3b. Bei der durch Erhitzen oder Photoanregung bewirkten Spaltung unterscheiden sich die Paare 1/3 nur geringfügig. Dies gilt selbst für Bestrahlungen in Argon bei 10 K. Unter diesen Bedingungen liefern die Anhydride la und 3a den gleichen Charge-transfer-Komplex 28a zwischen Tetramethylcyclobutadien und Phthalsäureanhydrid. Ein direkter Nachweis von Tetramethyltetrahedran gelingt auf diese Weise nicht.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19811141216
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  • 14
    Electronic Resource
    Electronic Resource
    Thermische Dehydrierung von 1-Sila-2,5-cyclohexadien zu Silabenzol (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 801-803 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal Dehydrogenation of 1-Sila-2,5-cyclohexadiene to SilabenzeneFlash pyrolysis of 1-sila-2,5-cyclohexadiene (1) yields silabenzene (2), which can be identified spectroscopically using matrix isolation in argon at 10 K. On the contrary the isomeric conjugated 1-sila-2,4-cyclohexadiene (3) forms under identical conditions only traces of silabenzene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150243
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  • 15
    Electronic Resource
    Electronic Resource
    Reversible Photoisomerisierung zwischen Silaethenen und Methylsilylenen (Methylsilandiylen)Diese 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. 864-865 
    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, 1785-1792
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19820941110
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  • 16
    Electronic Resource
    Electronic Resource
    Einfach substituierte BoraetheneHetero-π-Systeme, 14. Mitteilung. Diese Arbeit wurde von der Deutschen Forschungsgemeinschaft und dem Fonds der Chemischen Industrie unterstützt. - 13. Mitteilung: G Mayer, K. Schöttler, H. P. Reisenauer, Tetrahedron Lett. 26 (1985) 4079.Professor Hans Musso zum 60. Geburtstag gewidmet (1985)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 97 (1985), S. 1061-1063 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19850971221
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  • 17
    Electronic Resource
    Electronic Resource
    Reaction of Silicon Atoms with Acetylene and Ethylene: Generation and Matrix-Spectroscopic Identification of C2H2Si and C2H4Si Isomers (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1313-1317 
    Details
    ISSN: 1434-193X
    Keywords: Matrix isolation ; Silicon atoms ; Ab initio calculations ; Photochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Evaporation of silicon and consecutive cocondensation of the generated atoms with acetylene or ethylene in an argon matrix turnes out to be a new access to C2H2Si and C2H4Si isomers, respectively. In both cases the silicon atoms rather add to the π system than insert into C-H bonds, leading to cyclic silylenes as primary reaction products. In the Si/acetylene system the primary product is silacyclopro-penylidene (2), which shows the already known photo-chemical interconversion into additional C2H2Si species. On the other hand, cocondensation of silicon atoms with ethylene and subsequent irradiation lead to the matrix-isolation of three new C2H4Si isomers [apart from the known silacyclopropene (7) and silylacetylene (8)], namely silacyclopropylidene (10), s-trans-vinylsilylene (11), and the unsubstituted 1-silaallene (13). These species can be identified by comparison of their experimental IR spectra and those obtained by ab initio calculations. In a second reaction path, SiH2, which is formed as a byproduct from atomic silicon and hydrogen impurities, adds to the π system of acetylene, yielding silacyclopropene (7). Silacyclopropane (16), the analogous product of the reaction of SiH2 with ethylene, could not be observed.
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  • 18
    Electronic Resource
    Electronic Resource
    Silylenes of the Elemental Composition C2H4Si2: Generation and Matrix-Spectroscopic Identification (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1291-1295 
    Details
    ISSN: 1434-193X
    Keywords: Matrix isolation ; Silicon π systems ; Silacyclopropenylidenes ; Disilacyclobutadienes ; Photochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pulsed flash pyrolysis in combination with matrix isolation of three precursor molecules (10, 11, 12) led to the formation of silylsilacyclopropenylidene (1), which was identified by comparison of experimental and calculated (BLYP-6-31G*) IR spectra for both, unlabeled 1 and its perdeuterated isotopomer. Upon irradiation of matrix-isolated silylsilacyclopropenylidene (1) a second C2H4Si2 isomer, namely (silylethynyl)silylene (4) was formed. However, no evidence could be found for the formation of disilatetrahedrane or 1,2- or 1,3-disilacyclobutadiene.
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  • 19
    Electronic Resource
    Electronic Resource
    C3H4Si Species: Generation and Matrix-Spectroscopic Identification of Some Silacyclobutadiene Isomers (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1297-1305 
    Details
    ISSN: 1434-193X
    Keywords: Matrix isolation ; Ab initio calculations ; Photochemistry ; Silylenes ; Silaethenes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Flash pyrolyses of four suitable precursors - namely 1,1,1-trimethyl-2-propargyldisilane (32), its allenyl (34) and propynyl isomer (35), as well as 2-ethynyl-1,1,1,2-tetramethyldisilane (31) - lead to the formation of three C3H4Si species (7, 11, and 15). By examination of their photochemistry five additional compounds of the same composition (12, 13, 14, 17, and 18) were identified. Except ethynylsilaethene (18), all compounds observed are silylenes. Their identification is based on the comparison of the experimental and calculated (BLYP-6-31G*) IR spectra. Silacyclobutadiene (4) or silatetrahedrane (25) could not be detected.
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  • 20
    Electronic Resource
    Electronic Resource
    1,2,3,4-Tetra-tert-butyl-4-trimethylsilyl-4-sila-2-cyclobuten-1-yl: A Quantum Mechanical and ESR Study (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1107-1112 
    Details
    ISSN: 1434-193X
    Keywords: Photochemistry ; Radicals ; EPR spectroscopy ; Quantum mechanical calculations ; Silicon compounds ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Trisilane 7 has been synthesized as a potential photochemical precursor of tetra-tert-butylsilatetrahedrane (5) and/or tetra-tert-butylsilacyclobutadiene (6). Astonishingly, only one Si,Si bond is broken upon irradiation of 7 and the silacyclobutenyl radical 9 can be identified as the reaction product. The structure of radical 9, which in the absence of oxygen is persistent even at room temperature, has been elucidated by comparison of its experimental and calculated ESR spectra.
    Additional Material: 2 Ill.
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