Metal mediated reactions on porous silicon surfaces

Reactions that efficiently form SI-C bonds between silanes and unsaturated carbon-carbon bonds are widely known in molecular, solution phase chemistry . The possibility of covalent functionalization of porous silicon surfaces, which have similar chemical moieties to certain classes of molecular silan es, is intriguing. In this paper we describe approaches toward hydrosilylat ion of alkynes and alkenes and bis-silylation of alkynes utilizing known so lution phase Lewis acid and late transition metal catalysts on silicon hydr ide terminated porous silicon surfaces. Both EtAlCl2, and Wilkinson's catal yst, RhCl(PPh3)(3), effectively induce hydrosilylation of alkynes and alken es, Bis-silylation using palladium-based complexes, however, did not occur and thermally induced hydrosilylation took place in its stead. The Lewis ac id mediated hydrosilylation is extremely efficient and yields highly stabil ized surfaces. When Wilkinson's catalyst and palladium complexes are utiliz ed, on the other hand, extensive oxidation upon exposure to air is observed . (C) 1999 Academic Press.