Relationship between the magnitude of Jgem and the spatial orientation of α-substituents

Abstract

An empirical relationship between ΔJ_gem and a relative orientation of a methylene group attached to oxygen and sulphur, and two groups, sulphonyl and sulphinyl, has been experimentally determined. The empirical curve for oxygen shows marked similarity to a theoretically derived curve relating the magnitude of J_gem in the rotamers of methanol about the C–O bond. All four curves bear out the predictions of the theory of geminal coupling.