Structural and theoretical analysis of some mesogenic azines containing strong electron donor-acceptor groups

A structural and theoretical analysis of some mesogenic bis(phenylene)azines containing a methyl group on the azine system and strong electron donor-acceptor groups on the phenylene rings is reported. Starting from the X-ray molecular structures and with the support of semiempirical quantum mechanical calculations, the structural and conformational properties of the azines are analysed and compared with recent literature data on similar acetophenone azines. Some geometrical and electronic data of the molecules are also calculated and discussed in the paper, which may be useful for a better understanding of the mesophasic behaviour of the compounds.