A thermally stable silica/p-anisidine material was obtained by a sol-gel method in two steps: (a) p-anisidine was reacted with 3-chloropropyltrimethoxysilane using NaH as a base activator and; (b) the resulting product of this reaction, p-anisidinepropyltrimethoxysilane (AnPTMS), was condensed with tetraethylorthosilicate. The sol-gel materials were obtained by using the AnPTMS precursor at concentrations of 0.05, 0.15, 0.23, 0.35, and 0.46 mol L-1. The thermal stability of the organic attached groups increases with the AnPTMS precursor concentration added. For the 0.35 and 0.46 mol L-1 cases, the resulting materials were thermally stable up to 300 degreesC, under vacuum. (C) 2001 Academic Press.2412413416