A 1H NMR investigation of the conformational properties of 1,2-dimethoxybenzene

Abstract

The ¹H NMR spectrum of a sample of 1,2-dimethoxybenzene dissolved in a nematic solvent (I35) has been analysed to yield a set of partially-averaged dipolar couplings, D_ij. These are used to test models for the conformations adopted for the two OCH₃ groups relative to the ring. It is concluded that a single conformation, or a set of symmetry-related conformations is not consistent with the data. The dipolar couplings are used to derive the distribution among the 16 minimum energy structures which are possible if it is assumed that the C–O–C planes can only be either coplanar with, or perpendicular to, the phenyl ring plane.