The first examples of discotic liquid crystalline gemini surfactants

Abstract

Six novel gemini imidazolium salts tethered with hexaalkoxytriphenylene moieties were prepared by quaternization of imidazole nitrogen with ω-bromo-substituted triphenylene derivatives. Their chemical structures were examined by 1H NMR, IR, UV, MS, and elemental analyses. The mesomorphic properties of these discotic dimeric salts were investigated by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction studies. These triphenylene-imidazole-based gemini dimers with bromide as counter ion were found to exhibit liquid crystalline behavior over a wide temperature range and display ionic conductivity in the range of 10−6 to 10−5 S/m. These materials tend to form monolayer at the air–water interface.