Inter- and intra-molecular association of poly(diorganosiloxane)-αω-diols

Abstract

A spectroscopic study has been made of the association of the first three members of the dimethyl, methylvinyl, methylphenyl, and diphenyl series of poly(diorganosiloxane)-αω-diols. A detailed examination of intramolecular hydrogen bonding in the trisiloxane-1,5-diols has provided useful data on the stereochemistry of these compounds. Valency deviation due to the gem-diphenyl groups has been proposed to explain the high intramolecular hydroxy-frequency shift of hexaphenyltrisiloxane-1,5-diol relative to those given by the other trisiloxane-1,5-diols. A second intramolecular band given by hexaphenyltrisiloxane-1,5-diol has been assigned to interaction between the hydroxy-groups and the π-electrons of phenyl substituents.