Geometrical structures of the azines of substituted acetophenones

By drawing on measured values of dipole moments and Kerr constants and a study of vibrational spectra, it has been shown that the molecules of the symmetrical azines of the acetophenones exist as EE′ forms of the s-trans conformer, the angle of rotation of the azomethylidyne fragments around the N-N bond being 130±5° with the phenyl rings displaced out of the C=N bond planes by 35±5°.