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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