Discotic liquid crystal derived from zinc tetraaminophthalocyanine and perfluorooctanoic acid

Abstract

A novel kind of metallo-phthalocyanine derivative, zinc 2,9,16,23-tetraaminophthalocyanine perfluorooctanoate (Zn-APc-pFOA), was synthesized from zinc tetraaminophthalocyanine and perfluorooctanoic acid. The chemical structure, liquid crystalline behavior, and electrorheological properties were characterized by the use of various experimental techniques, methods, and instruments, including FT-IR and UV-vis spectroscopy, 1 H-NMR, x-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, polarized optical microscopy, the four-point method, a relative permittivity test instrument, and a rotating viscometer. Zn-APc-pFOA shows a discotic hexagonal columnar mesophase over a wide temperature range. The dielectric constant and conductivity of Zn-APc-pFOA are 11.4 and 6.34 × 10 −3 S cm −1 , respectively. The 20 V% silicone oil-Zn-APc-pFOA fluid shows an electrorheological (ER) effect. Zn-APc-pFOA is a semiconductor with a high dielectric constant, causing a mismatch of conductivity and dielectric constant between the Zn-APc-pFOA and silicone oil. Furthermore, some synergistic effect could occur between the semiconducting property and the molecular orientation of the discotic liquid crystals in Zn-APc-pFOA suspensions, resulting in a high ER effect.

Self‐Assembly and Molecular Electrical Switching Property of Phthalocyanine‐Based Liquid‐Crystalline Poly(Styrene Sulfonic Acid) Compounds

“…Zinc tetraaminophthalocyanine (ZnPc‐NH 2 ) was synthesized by reduction of zinc tetranitrophthalocyanine according to the previous report. [ 28 ] The LC reaction intermediates 6‐cholesteryloxy‐6‐oxohexanoic acid (CH‐COOH) and 10‐cholesteryloxy‐10‐oxodecanoic acid (CD‐COOH) were synthesized in an esterification reaction between cholesterol and alkyl dichlorides including adipoyl dichloride and decanedioyl dichloride. For example, decanedioyl dichloride (2.39 g, 0.01 mol), cholesterol (4.01 g, 0.01 mol), and pyridine (5.6 mL, 0.07 mol) were added successively to a three‐necked flask filled with 30 mL of THF.…”

Synthesis of novel azo-bridged phthalocyanines and their toluene vapour sensing properties

“…Pcs display a number of unique properties, such as increased stability, architectural flexibility, diverse coordination properties, and improved spectroscopic characteristics [2], which make them of great interest in various scientific and technological areas. Pcs were first developed as dyes and pigments [1], and since then have been used in various fields such as in medical applications [3], gas sensors [4,5], electrochromism in display devices [6], liquid crystals [7], and nonlinear optics [8], photovoltaic solar cells [9], electrophotography [10], molecular electronics [11], and Langmuir-Blodgett films [12].…”