Rotational isomerism of NN′-dimethyl-α,ω-bis(benzoylamino)alkanes
Abstract
The low-temperature 1H n.m.r. spectra of PhCO·N(Me)·(CH2)n·N(Me)·COPh show four signals for the methyl groups when n 3, which are attributable to the presence of three rotational isomers. Only one isomer was detectable over a wide temperature range when n= 2. The rotational energy barriers have been measured and are close to that reported for NN-dimethylbenzamide.