PROTON MAGNETIC RESONANCE SPECTRA OF VINYL-METALLIC COMPOUNDS - SOLVENT EFFECTS UPON SPECTRA OF ALPHA-CHLOROVINYLTRICHLOROSILANE AND ALPHA-CHLOROVINYLTRIMETHYLSILANE

A study has been made of the effects of solvents and concentration on the chemical shifts and coupling constants of α-chlorovinyltrichlorosilane (α-CTS) and α-chlorovinyltrimethylsilane (α-CTMS). The chemical shifts of the vinyl protons show a marked concentration dependence in hydrogen-bonding solvents and in benzene, particularly in the case of α-CTS. These shift changes are interpreted in terms of solute-solvent and solute-solute interactions. Equilibrium constants have been deduced, from the shift data, for the complexing reactions of α-CTS with various solvents and for self-association in cyclohexane. A solvent and concentration dependence of the geminal proton coupling constant was observed and was most pronounced for α-CTS. The shift and coupling constant changes have been interpreted in terms of solvent induced electron density changes in the bonding orbitals. © 1968 Academic Press Inc., New York, N. Y. 10003.