Is the Effective Size of an Alkyl Group a Gauge of Dynamic Gearing?

Abstract

Abstract This paper presents a critical discussion of the perceived similarity between alkyl groups and mechanical gears. Specifically, we examine the notion that the availability of “free spaces” between the ligands of the central atom in an alkyl group leads to a reduction in the steric requirements of the group and, hence, to an effect on the rate of conformational interconversion. It is concluded that there is no compelling experimental evidence to support the operation of this type of dynamic gear effect.