Columnar mesomorphism of bi- and trinuclear Ni(II), Cu(II), and VO(II) cis-enamonoketone complexes with low symmetry.

New enaminoketone tetradentate bi- and trinuclear complexes creating columnar mesophases are reported. Various combinations of nickel, copper, or vanadyl ions were applied as metallic centers. Because of the bowlike structure of chelating centers and the low molecular symmetry (Cs) the bivanadyl complexes form two diastereoisomers, which were separated. The superexchange coupling of the electron spins of paramagnetic centers copper-copper and vanadyl-vanadyl was found for binuclear complexes in ESR studies.