ISSN:
0009-2940
Keywords:
Aluminosiloxanes
;
1,3-Diorganodisiloxanes
;
Siloxane cleavage by aluminium halides
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
sym-Diorganodisiloxanes RH2SiOSiH2R (R = C2H5, 7; C2H3, 8; C2H, 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 AlCl3 leads to the formation of organo-(chloro)silanes and aluminosiloxane dimers [RH2SiOAlCl2]2 (R = C2H5, 10; C2H3, 11; C2H, 12). Crystal structure determinations of 11 and 12 reveal a planar centrosymmetrical SiOAl2OSi skeleton with three-coordinate oxygen atoms and tetrahedral four-coordinate aluminum atoms. Treatment of 7-9 with Me2AlCl yields volatile dimethylaluminumorganosilyl oxides [RH2SiOAlMe2]x (R = C2H5, 13; C2H3, 14; C2H, 15; x = 2, 3, 4). NMR studies confirm the presence of more than one oligomer in solutions of these compounds. The asymmetrical compound (HC-CSiH2O)2Me3Al2Cl (16), resulting from small amounts of MeAlCl2 in the Me2AlCl 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.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931261204
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