Rod-like liquid crystals of organic transition metal complexes. I. Reversible transformation between blue smectogen and red nematogen

作者：Kazuchika Ohta, Hiroshi Ema, Yasue Morizumi, Takuya Watanabe, Tetsuya Fujimoto, Iwao Yamamoto · 发表于：Liquid Crystals · 年份：1990 · DOI：10.1080/02678299008047350 · 被引用次数：22 · 研究领域：Lanthanide and Transition Metal Complexes、Liquid Crystal Research Advancements、Surfactants and Colloidal Systems

Two novel types of transition-metal-containing liquid crystals, bis(p-n-koxydithiobenzoato)nickel(II) (abbreviated as (C n O-DTB)2Ni), and (p-n-alkoxydithiobenzoato)(p-n-alkoxyperthiobenzoato)nickel(II) (abbreviated as (C n O-DTB)(C n O-PTB)Ni), were synthesized. It was found that the (C n O-DTB)2Ni complex for n = 8 has smectic H and C mesophases, and that the (C n O-DTB)2Ni complexes for n = 4 and 8 easily transform into the corresponding monoperthio complexes, n O-PTB)Ni, by heating at temperatures between 230°C and 285°C. It was confirmed that the transformation originates from an intermolecular reaction between the (C n O-DTB)2Ni complexes at high temperatures, and that the origin of the extra sulphurs in the resulting (C n O-DTB)(C n O-PTB)Ni complexes is the neighbouring (C n O-DTB)2Ni complexes. Interestingly, each of the (C n O-DTB)(C n O-PTB)Ni complexes (n = 4 and 8), has nematic mesophase and exhibits a unique double melting behaviour via the nematic phase, which is the first example in liquid crystals. The reversible transformation between the blue smectic rod-like (C n O-DTB)2Ni complex and the red nematic Λ-like (C n O-DTB)(C n O-PTB)Ni complex is possible.