Synthesis and Characterization of Silica-Bound Propanesulfonic Acid.

摘要

Colloidal silica was prepared by Stober's method. After the dispersion was transferred to Dimethyl Formamide, reaction with mercaptopropyltrimethoxysilane gave silica with 0.35 mequiv/g of bound mercaptopropyl groups. The mercaptan was oxidized with tertbutylhydroperoxide to give 0.17 mequiv/g of bound sulfonic acid and leave 0.076 mequiv/g of unreacted thiol. The CP/MAS 13C NMR spectrum gives evidence of several partially oxidized intermediates, including a significant amount of disulfide. This is the first example of a functional group transformation on silica in a colloidal state. (AW)