Synthesis and mesomorphic properties of unsymmetrical bent-core compounds containing 1,3-phenylene or 2,7-naphthylene as the central unit

Abstract

The synthesis and mesomorphic properties of four new homologous series of unsymmetrical bent-core compounds with 1,3-phenylene or 2,7-naphthylene as the central unit are reported. These compounds contain an α-methylcinnamoyloxy bridging group in one of the arms. Three types of mesophases, namely, N, B₁ and B₂ are observed in these compounds. The rarely observed transitions N to B₁ and N to B₂ have been observed in some of the compounds derived from 2,7-dihydroxynaphthalene. In one of the compounds derived from resorcinol, textural features of both B₁ and B₂ phases appear simultaneously on cooling the isotropic phase. The mesophases were characterized using conventional techniques.