Synthesis and phase transition behaviors of novel benzoic acids with different alkylthio groups

Abstract

We synthesized and evaluated liquid crystalline (LC) phases of novel benzoic acids with different alkylthio groups at each para-position. Their LC phases were characterized with polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The present molecules solely form a nematic (N) regime, owing to spontaneous carboxylic dimerization. It was found that the number of carbons in the alkylthio groups strongly correlated with transition temperatures as well as nematogenic stability; odd-even effects. Based-on WAXD measurements with aligned specimens, an alkylthio analogue exhibited the enhanced cybotactic clusters compared to an alkoxy analogue.