New Heterocyclic Mesogens with Benzopyran-2 H-One Moiety

Abstract

Mesogen with benzopyran-2 H-one moiety are rare. However, Trivedi et al. have reported mesogenic benzopyran-2 H-one. Recently, Vora et al. have reported mesogenic polymers with benzopyran-2 H-one moiety and evaluated its fluorescent behaviour. In view of the rarity of mesogens with benzopyran-2 H-one moiety and their potential as fluorescent compounds, homologous series of 3-Bromo-4-Methyl-2-oxo-2 H-1-benzopyran-7-yl-4′-n-alkoxy benzoates was synthesized and the mesomorphic behaviour has been studied. Lower members are non-mesogenic where as higher members of the series exhibit monotropic smectic phase. Transition temperatures are also identified using DSC. The thermal stabilities of present series is compared with the corresponding homologous series of benzopyran-2 H-one derivatives. All the synthesized compounds are characterized by elemental analysis and spectroscopic studies.

Key Words:

• LC synthesis
• heterocyclic
• benzopyran