Discotic Liquid Crystals of Transition Metal Complexes 81: Enantiotropic Nematic Mesomorphism and Helical Formation of Bis[1(p-n-alkoxybiphenyl)-3-alkylpropane- 1,3-dionato]copper(II) Complexes

Abstract

Abstract Five new bis(β-diketonato) copper (II) complexes, bis[1-(p-n-alkoxybiphenyl)-3-alkylpropane-1,3-dion- ato] copper (II) complexes [abbreviated as CnO-Comp-Cm: n = m = 4, 8, 12; (n. m) = (8, 4), (12. 4)] have been synthesized and characterized. It was found that the complexes exhibit nematic mesomorphism. C4, C8O-Comp-C4 and C4O-Comp-C4 have an enantiotropic nematic mesophase. C12O-Comp-C4, C8O-Comp-C8 and C1220-Comp-C12, have not a discotic columnar mesophase but a monotropic nematic mesophase: moreover, they exhibit helical formation, which can be thought to be extremely close to discotic columnar mesomorphism.