140202-73-9Relevant articles and documents
Reactions of incompletely-condensed silsesquioxanes with pentamethylantimony: A new synthesis of metallasilsesquioxanes with important implications for the chemistry of silica surfaces
Feher, Frank J.,Budzichowski, Theodore A.,Rahimian, Kamyar,Ziller, Joseph W.
, p. 3859 - 3866 (2007/10/02)
The reactions of the incompletely condensed polyhedral oligosilsesquioxanes (c-C6H11)7Si7O9(OH) 3 (1a), (c-C6H11)7Si7O 9(OTMS)(OH)2 (2a), (c-C6H11)7Si7O 9(OTMS)2(OH) (3a), (c-C6H11)8Si8O10(OH) 2 (4a), and (c-C6H11)7Si7O10(OH) (5a) with excess Me5Sb result in the formation of the corresponding stibonium-substituted silsesquioxanes (c-C6H11)7Si7O 9(OSbMe4)3 (1b), (c-C6H11)7Si7O 9(OTMS)(OSbMe4)2, (2b), (c-C6H11)7Si7O 9(OTMS)2(OSbMe4) (3b), (c-C6H11)8Si8O 10(OSbMe4)2 (4b), and (c-C6H11)7Si7O 10(OSbMe4) (5b) in high yields. These stibonium siloxides show enhanced reactivity toward main-group and transition-metal halide complexes and provide an alternative route for the preparation of metallasilsesquioxanes. The reaction of 1a with 1 equiv of Me5Sb is much faster than the reactions of Me5Sb with silanols containing fewer than three mutually hydrogen-bonded siloxy groups. This suggests that multiply hydrogen-bonded surface sites are more reactive toward nucleophilic organometallic reagents than either isolated surface silanols or isolated pairs of geminally or vicinally hydrogen-bonded siloxy groups.
