FLUORESCENCE-SPECTRA OF NAPHTHOLS DURING SOL TO GEL TRANSITION OF TETRAETHOXY SILANE BY HCL CATALYST

The fluorescence and fluorescence-excitation spectra of 1- and 2-naphthol during sol to gel transition of tetraethoxy silane (TEOS) catalyzed by HCl have been observed as a function of time. The fluorescent level inversion of 1-naphthol from 1La to 1Lb occurred after the gelation of TEOS. On the other hand, the fluorescence spectrum of 2-naphthol molecules during the sol-gel-xerogel transition was almost unchanged. Observation of the fluorescence spectra of 1-naphthol molecules is a useful photophysical probe for studying the sol-gel-xerogel transition of metal alkoxides such as TEOS on a molecular level. © 1990.