Design and Synthesis of Novel Calamitic and Discotic Materials Based on the Photorefractive Carbazole Unit

• Published in: Molecular Crystals and Liquid Crystals Vol. 518; no. 1; pp. 84 - 100
• Main Authors: Manickam, M., Iqbal, P., Spencer, N., Ashton, P. R., Kumar, S., Donovan, K. J., Preece, J. A.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis Group 01.01.2010; Taylor & Francis Ltd
• Subjects: Alkylation; Anisotropic ordering; calamitic liquid crystals; carbazole; Carbazoles; Carboxylic acids; Chemical compounds; Crystals; Derivatives; Differential scanning calorimetry; discotic liquid crystals; Liquid crystal polymers; Liquid crystals; mesogenic; Phase transitions; photorefractive; Photorefractivity; Synthesis
• ISSN: 1542-1406; 1563-5287; 1527-1943
• DOI: 10.1080/15421400903568054

The incorporation of photorefractive molecular units, such as carbazole, into anisotropic materials (liquid crystals) may offer many advantages over conventional electrical poling of photorefractive polymers. Thus, a series of symmetric 3,6-disubstituted carbazole derivatives with well-known biphenyl and triphenylene liquid-crystalline moieties was synthesized and characterized. These modifications were achieved by the esterification of bishydroxy carbazole derivatives with monoalkylated biphenyl carboxylic acids and alkylation of bisacylated bromo- derivatives of carbazole with monohydroxy pentaalkoxy triphenylene. The pure compounds are not liquid-crystalline, even when doped with trinitrofluorenone (TNF), unlike triphenylene/carbazole materials that we reported previously. These compounds, although not liquid-crystalline, may be of interest in the field of photorefractivity.