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A synthetic route to poly(silyl)methanes via poly(phenylsilyl)methanes and poly(bromosily)methanes
Author(s) -
Hager Rudolf,
Steigelmann Oliver,
Müller Gerhard,
Schmidbaur Hubert
Publication year - 1989
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19891221111
Subject(s) - chemistry , tetrahydrofuran , silylation , hydride , silane , molecule , medicinal chemistry , catalysis , inorganic chemistry , hydrogen , organic chemistry , solvent
A three‐step synthesis is presented for di‐ and tri(silyl)methane, two feedstock gases for the chemical vapour deposition of amorphous hydrogenated silicon/carbon alloys (a‐SiC:H). Chloro(phenyl)silane and di‐ or trihalomethanes react with magnesium in tetrahydrofuran to give high yields of bis‐ and tris(phenylsilyl)methane, respectively. The two products can be converted into bis‐ and tris(bromosilyl)methane by treatment with anhydrous hydrogen bromide. Bromide/hydride substitution in these precursors is accomplished with lithium aluminum hydride in a two‐phase system using a phase‐transfer catalyst. The compounds CH 2 (SiH 2 Ph) 2 , CH(SiH 2 Ph) 3 , CH 2 (SiH 2 Br) 2 , CH(SiH 2 Br) 3 , CH 2 (SiH 3 ) 2 , and CH(SiH 3 ) 3 have been characterized by standard spectroscopic methods, and the crystal and molecular structure of CH(SiH 2 Ph) 3 has been determined by single‐crystal X‐ray diffraction. The molecule adopts a conformation with crystallographic C 3 symmetry. This result is discussed with regard to the structure of related molecules with three substituents of potential C s symmetry at a tetrahedral center.