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(Ethyl‐, Ethenyl‐ and Ethynylsilyloxy)aluminum Compounds Generated by Heterolytic Cleavage of 1,3‐Disubstituted Disiloxanes
Author(s) -
Bissinger Peter,
Paul Martin,
Riede Jürgen,
Schmidbaur Hubert
Publication year - 1993
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.19931261204
Subject(s) - chemistry , silanes , heterolysis , crystal structure , hydrolysis , cleavage (geology) , crystallography , medicinal chemistry , molecule , stereochemistry , organic chemistry , catalysis , silane , geotechnical engineering , fracture (geology) , engineering
sym ‐Diorganodisiloxanes RH 2 SiOSiH 2 R (R = C 2 H 5 , 7 ; C 2 H 3 , 8 ; C 2 H, 9 ) are prepared by hydrolysis of organo(bromo)silanes which are available in high yields by the reaction of organo‐(phenyl)silanes with liquid HBr. Asymmetrical cleavage of these disiloxanes with AlCl 3 leads to the formation of organo‐(chloro)silanes and aluminosiloxane dimers [RH 2 SiOAlCl 2 ] 2 (R = C 2 H 5 , 10 ; C 2 H 3 , 11 ; C 2 H, 12 ). Crystal structure determinations of 11 and 12 reveal a planar centrosymmetrical SiOAl 2 OSi skeleton with three‐coordinate oxygen atoms and tetrahedral four‐coordinate aluminum atoms. Treatment of 7–9 with Me 2 AlCl yields volatile dimethylaluminumorganosilyl oxides [RH 2 SiOAlMe 2 ] x (R = C 2 H 5 , 13 ; C 2 H 3 , 14 ; C 2 H, 15 ; x = 2, 3, 4). NMR studies confirm the presence of more than one oligomer in solutions of these compounds. The asymmetrical compound (HC‐CSiH 2 O) 2 Me 3 Al 2 Cl ( 16 ), resulting from small amounts of MeAlCl 2 in the Me 2 AlCl used, is isolated as a byproduct in the synthesis of 15 . The crystal structure of 16 shows a disorder of the molecules leading to pseudosymmetry with a center of inversion.