CHEMICAL ATTACHMENT OF CHLOROSILANES TO SILICA - A 2-STEP AMINE-PROMOTED REACTION

A method has been developed by which chlorosilanes can be attached to the surface of silica by way of a Si(s)-O-Si linkage at room temperatu re. The process uses an amine attached to the surface to promote the r eaction. Polymerization of the chlorosilane is avoided by performing t he experiment in a two-step process, and this can be extended to build a multilayered silane in a well-defined manner. Direct evidence to su pport our claim is provided by infrared spectroscopy. The two-step pro cess suggests that the mechanism of silanization in heterogeneous syst ems involves formation of a pentacoordinate intermediate in which the amine base is attached to the surface silanol rather than the reacting silane.