Preparation, structure, and reactivity of pentacoordinate disilanes bearing an 8-charcogeno-1-naphthyl group and a heteroatom on the same silicon atom

The pentacoordinate disilanes bearing an 8-chalcogeno-1-naphthyl group and an ethoxy group (or a fluorine atom) on the same silicon center are found t o be thermally stable, in sharp contrast to the thermal lability of the ana logous disilanes coordinated by the group 15 elements, such as nitrogen and phosphorus, to alpha -elimination of the ethoxysilane (or fluorosilane) to generate the base-coordinated silylenes. As the reasons for this different behavior, two possibilities are pointed out as follows: (1) the nitrogen-c oordinated disalanes are destabilized due to the distortion of the naphthyl moiety, and (2) silylenes are more stabilized by coordination with the gro up 15 elements than with the group 16 elements. (C) 2001 John Wiley & Sons, Inc.