Synthesis of new monodendrons, gallic acid derivatives, self- assembled in a columnar phase

ABSTRACT

This article describes the synthesis and liquid crystal properties of new compounds that are derived from gallic acid. All the compounds were characterised by ¹H and ¹³C nuclear magnetic resonance spectroscopy (¹H NMR and ¹³C NMR), Infrared spectroscopy (IR) and Elemental analysis (CHN). The mesophases of these compounds were characterised using polarising optical microscopy (POM), differential scanning calorimetry (DSC) and SAXS measurements. The morphology of the surface of the films was investigated using atomic force microscopy (AFM). Compounds 9 and 13, which remain in a supercooled state until room temperature, do not exhibit liquid crystalline behaviour. The other compounds (i.e., 5, 7 and 8) self-assemble into tubular supramolecular architectures generating hexagonal columnar (Col_h) mesophases, which was confirmed by SAXS measurements.

GRAPHICAL ABSTRACT

KEYWORDS:

• Gallic acid
• liquid crystal
• hexagonal columnar mesophases

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors wish to thank Conselho Nacional de Pesquisa e Desenvolvimento (CNPq– Brazil) [440619/2014-9] for financial support. The LNLS is acknowledged for supplying the SAXS beam time (proposal 16960) and the financial support from CELESC P&D 5697-8712/2012.