Hexylene-and phenylene-bridged polymethylsiloxane xerogels X-2 and X-4,
respectively, were prepared by the sol-gel hydrolysis and condensation of 1,
6-bis(diethoxymethyl-silyl)hexane 1 and 1, 4-bis(diethoxymethysilyl)benzene
2 under acidic and basic conditions. These polymerizations afforded network
polymers in the form of wet gels within several hours. The gels were
processed to afford xerogels whose characteristics (determined by solid
state 13C and 29Si CP MAS NMR spectroscopy and
nitrogen sorption porosimetry) were compared and contrasted with those of
their analogous polysilsesquioxanes. 29Si CP MAS NMR indicates a
high, degree of hydrolysis and polycondensation; porosimetry measurements
reveal that the materials have significant surface areas, save for the
acid-catalyzed hexylene gels X-2.