Rufigallol-based self-assembled supramolecular architectures

Abstract

Discotic liquid crystals have been attracting growing interest not only because of the fundamental importance as model systems for the study of charge and energy transport but also due to their potential application in organic electronic devices. The 1,2,3,5,6,7-hexahydroxy-9,10-anthraquinone, commonly known as rufigallol, is one of the earliest systems reported to form columnar mesophases. Over the past 25 years, more than 100 discotic liquid crystals based on this core have been realized and studied for various physical properties. This review summarizes synthesis and thermal behaviour of all these materials. A brief summary of various physical studies on these materials has also been given.

Phase Transitionsand recent advances in liquid-crystals research

“…An excellent review summarizing synthesis and thermal behavior of these materials has appeared in reference [74]. Discotic molecules are of interest for their intriguing supramolecular architectures.…”

Hierarchical discs

“…Grimshaw and Haworth reported its purification in 1956 (39). Since then little further work has appeared and no new efficient methods to prepare rufigallol were reported.…”

Microwave-assisted synthesis of novel mixed tail rufigallol derivatives

“…Compound 4t showed crystal-to-isotropic transition at 49.68 • C (ΔH = 100.94 kJ mol −1 It should be noted that only a few compounds are reported in the literature based on branched-chain rufigallol derivatives. Bisoyi and Kumar [35,43] have reported rufigallol derivatives with 3,7-dimethyloctyl branched chain at 1-and 5-position, keeping other positions intact with simple alkyl chains. They have also demonstrated one compound with 3,7-dimethyloctyl branched chain at 2-,3-,6-,7-positions, which was found to exhibit Col h mesophase at room temperature [43].…”

“…Bisoyi and Kumar [35,43] have reported rufigallol derivatives with 3,7-dimethyloctyl branched chain at 1-and 5-position, keeping other positions intact with simple alkyl chains. They have also demonstrated one compound with 3,7-dimethyloctyl branched chain at 2-,3-,6-,7-positions, which was found to exhibit Col h mesophase at room temperature [43]. Interestingly, the attachment of branched chain in all the six positions of rufigallol moiety results in the loss of LC properties of the derivative [35].…”