Discotic Liquid Crystals of Transition Metal Complexes, 1: Bis[1,3-di(p-n-octylphenyl)propane-1,3-dionato]copper(II) and Bis[1,3-di(p-n-octyloxyphenyl)propane-1,3-dionato]copper(II)

Abstract

It was found that the bis β-diketonato copper (II) complexes IIa, IIb have discotic mesophases; IIa(D₁:76.1 - 117.2°C, D₂:117.2 - 141.6°C), IIb(D: 82.5 - 173.3°C), and that the corresponding β-diketone ligands Ia, Ib have classical mesophases; Ia (Smectic: 28.5 - 60.7°C), Ib(Smectic:72.3 - 83.6°C). Ila has two discotic mesophases, which is the first example exhibiting discotic mesogen polymorphism. The temperature range of mesophase for β-diketone ligand with octyloxy chains lb is narrower than that of the ligand with octyl chains la, and on the contrary the range of the Cu(II) complex with octyloxy chains IIb is wider than that of the Cu(II) complex with octyl chains IIa. It is the first example of such substituent effect in mesomorphism.