Flying-seed-like liquid crystals. Part 4: a novel series of bulky substituents inducing mesomorphism instead of using long alkyl chains

Abstract

We have synthesized a novel series of flying-seed-like derivatives (3a~g) based on phthalocyaninato copper(II) (abbreviated as PcCu) substituted by bulky groups {PhO (a), Thus, we have revealed that mesomorphism could be induced by these novel bulky substituents instead of using long alkyl chains, and that the mesophase structures were greatly affected by the number and position of methoxy groups. Especially, it is very interesting that the derivatives having methoxy group(s) at the meta position(s), 3c, 3e, 3f and 3g, tend to show enantiotropic mesophase(s), whereas neither the derivative having no methoxy group, 3a, nor the derivative having a methoxy group at the para position, 20 3d, show a mesophase.

Discotic liquid crystals of transition metal complexes 52: Synthesis and homeotropic alignment of liquid crystalline phthalocyanine-fullerene dyad bridged by vanillin

“…Therefore, presence of the methoxy group may be a key point on the homeotropic alignment. We have previously reported that a novel type of flying-seed-like liquid crystals show mesomorphism despite absence of long chains [36][37][38][39][40][41]. For example, (m-CH 3 OPhO) 8 PcCu (8) in Fig.…”

“…8[A] shows mesomorphism. The mesomorphism of flying-seed-like liquid crystals is originated from the free rotation or flip-flop of bulky substituents, e.g., m-CH 3 OPhO groups [39]. Therefore, the o-CH 3 OPhO (VAN) group in (C 14 S) 6 PcCu-VAN-C 60 (3b) may also enhance the mesomorphism and homeotropic alignment.…”

Effect of the Nature of Substituents and Metal Atom on Mesomorphic Properties of Octasubstituted phthalocyanines with 4-(1-methyl-1-phenylethyl)phenoxy Groups

“…Мезофаза соединения 1а существует в достаточно широком интервале температур, равном 87 °С (табл. 2), что характерно для «flying-seeds-like» мезогенов [13,14].…”

“…В настоящее время интерес ученых вызывают мезогенные соединения с заместителями типа «flying-seeds-like» (семян-«крылаток»), особенностью которых является отсутствие протяженных алкильных заместителей [13,14] и чрезвычайно широкий интервал существования мезофазы. Среди таких соединений -тетразамещенные фталоцианины с фрагментами 4-кумилфенола (4-(1-метил-1-фенилэтил)фенола).…”

Synthesis of Cu(II) and Ni(II) Phthalocyanines Bearing Nitro and 4-(1-Methyl-1-phenylethyl)phenoxy Groups

“…[1,4,17,18] It was later shown that the presence of aliphatic substituents was not absolutely necessary for the formation of columnar mesophases. [19] The so-called flying-seeds-like compounds (FSLM) synthesized by Ohta et al, [20][21][22][23][24] unlike classical discotic mesogens, did not contain extended aliphatic substituents in the molecule. Nevertheless, the mesophase was formed due to the filling of free volumes at the periphery of the columns with mobile aromatic substituents.…”