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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 12712-12720 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1434-4475
    Keywords: Keywords. Matrix isolation; ab initio Calculations; Photoisomerizations.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary.  Codeposition of thermally generated silicon atoms with methanol in an argon matrix at 12 K led to the formation of methoxysilylene (4) by insertion of the silicon atom into the O–H bond of the substrate. Its spectroscopic identification was aided by calculated IR spectra and deuteriation experiments. Both the s-cis (4a) and the s-trans conformer (4b) of methoxysilylene could be observed and interconverted into each other photochemically.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 109 (1997), S. 1785-1787 
    ISSN: 0044-8249
    Keywords: Ab-initio-Rechnungen ; Isomerisierungen ; Matrixisolation ; Photochemie ; Radikale ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    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.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 769-776 
    ISSN: 1434-193X
    Keywords: Matrix isolation ; IR spectroscopy ; Photochemistry ; Two-photon process ; Excitons ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Irradiation of acetylene (4) in an argon matrix with an ArF laser (λ = 193 nm) yields the ethynyl radical C2H· (5) and C2 (6). If the same wavelength is used to irradiate 4 in a xenon matrix, only the infrared signal of the compound Xe-C2 (7) can be detected. The same band is found on irradiation at λ = 248 nm (KrF laser) in a xenon matrix, despite the fact that acetylene (4) does not absorb light of this wavelength. Irradiation of the T-shaped acetylene dimer 9 in an argon or xenon matrix at λ = 193 nm yields butadiyne (11) and vinylacetylene (12). However, irradiation with a KrF laser (λ = 248 nm) in a xenon matrix additionally yields cyclobutadiene (13). The dependence of the mechanisms of the fragmentation and dimerization of acetylene (4) on the matrix material is discussed.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1291-1295 
    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.
    Type of Medium: Electronic Resource
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  • 7
    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.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1434-193X
    Keywords: Matrix isolation ; IR spectroscopy ; Photochemistry ; Diradicals ; Isomerizations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Bicyclopropylidene (3) and 1,2-dimethylenecyclobutane (7) have been irradiated in rare-gas matrices. If 1,2-dimethylenecyclobutane (7) is exposed to the light of a KrF excimer laser (λ = 248 nm), an isomeric species is produced, showing an absorption at 793.1 cm-1 (argon matrix) or 791.2 cm-1 (xenon matrix) in the IR spectrum. The back reaction can be induced with light of λ = 254 nm. This photochemical interconversion, together with the comparison between the experimental and calculated band positions, supports the assignment of the IR absorption near 790 cm-1 to tetramethyleneethane (5).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1285-1290 
    ISSN: 1434-193X
    Keywords: Matrix isolation ; Silicon π systems ; Silacyclopropenylidenes ; Photochemistry ; Density functional calculations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Flash pyrolysis of 1,1-diethynyl-2,2,2-trimethyldisilane (16) and triethynylsilane (18) led to the formation of two silylenes of the elemental composition C4H2Si, namely diethynylsilylene (10) and ethynylsilacyclopropenylidene (7), which were isolated in an argon matrix at 10 K. Both compounds could be photoconverted into another isomer, butadiynylsilylene (9). The identification of these reactive intermediates is based on the comparison between the experimental and calculated IR spectra for the parent compounds as well as for their dideuterated and fully 13C-labeled isotopomers.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1434-193X
    Keywords: Matrix isolation ; Ab initio calculations ; Silicon atoms ; Photochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cocondensation of thermally generated silicon atoms with hydrogen cyanide in an argon matrix can be used as an access to compounds of the composition CHNSi and CNSi. Isolation, matrix-spectroscopic identification and photo-chemical behavior of these species are described. Structural assignments are made by the comparison of experimental with calculated IR spectra.
    Type of Medium: Electronic Resource
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