Crystal structure of N,N′-dibenzyl-3,3′-di-meth-oxy-benzidine

摘要

The title compound, (systematic name: N,N′-dibenzyl-3,3′-dimeth-oxy-1,1′-biphenyl-4,4′-di-amine), C28H28N2O2, was synthesized by the reduction of a Schiff base prepared via a condensation reaction between o-dianisidine and benzaldehyde under acidic conditions. The mol-ecule lies on a crystallographic inversion centre so that the asymmetric unit contains one half-mol-ecule. The biphenyl moiety compound is essentially planar. Two intra-molecular N—H?O hydrogen bonds occur. The dihedral angle between the terminal phenyl and phenyl-ene rings of a benzidine unit is 48.68?(6)°. The methyl-ene C atom of the benzyl group is disordered over two sets of sites, with occupancy ratio 0.779?(18):0.221?(18). In the crystal, mol-ecules are connected by hydrogen bonding between o-dianisidine O atoms and H atoms of the terminal benzyl groups, forming a one-dimensional ladder-like structure. In the data from DFT calculations, the central biphenyl showed a twisted conformation.