Discotic liquid crystals of transition metal complexes 43: the effect of the length of alkoxy chains at the m-positions in phenoxy groups on mesomorphism for the novel octaphenoxyphthalocyaninato copper(II) and terbium(III) complexes

Abstract

We have synthesised two novel series of octaphenoxyphthalocyaninato copper(II) complexes, (m-C _n O)PcCu (n = 2–10: 2b–f), and bis(octaphenoxyphthalocyaninato)terbium(III) complexes, [(m-C _n O)Pc]₂Tb (n = 2–10: 3b–f), which were substituted by dodecyloxy chains at the p-positions in the phenoxy groups and various length of alkoxy chains at the m-positions in the phenoxy groups. Their mesomorphic properties were investigated by polarising microscopy, differential scanning calorimetry (DSC) and temperature-dependent X-ray diffraction techniques. The Cu complex (2b) and the Tb complexes (3b–d), having shorter chains at the m-positions in the phenoxy groups, exhibited a lamellocolumnar (Col_L) mesophase. Moreover, it was revealed that the complexes (2 and 3) tend to change their mesophases of the order of Col_h → Col_L → Col_r → Cub → Col_tet with elongating the length of the alkoxy chains at the m-positions.

^†Reference [1].

Keywords:

• discotic liquid crystal
• columnar mesophase
• phthalocyanine
• metallomesogen

Acknowledgement

This work was supported by a Grant-in-Aid for Science Research (19022011) in the Priority Area ‘Super-Hierarchical Structures’ from the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Notes

^†Reference [1].