Synthesis and study of mesomorphic properties of unsymmetrical cyclohexanone-derived bis-chalcones

A series of (2E,6E)-2-(4-n-alkoxybenzylidene)-6-((benzo[d][1,3]dioxol-6-yl)methylene)cyclohexanones were synthesised by stepwise condensation reactions from cyclohexanone. The optical and thermal analysis of the series indicated the mesomorphic properties of some derivatives. The compounds with C7–C16 substituents showed the nematic phases in the range of 90–73°C. The single crystal X-ray analysis confirms the head to tail packing arrangement.