New hockey stick shaped amino allylidene (‒N˭CH‒CH˭CH) based compounds: Effect of linkage group on mesomorphic properties

GRAPHICAL ABSTRACT

ABSTRACT

Two nonlinear hockey stick shaped homologous series based on three linking groups have been synthesized and characterized by elemental analyses and spectroscopic techniques. The mesomorphic properties of these compounds were observed by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). In this present investigation, we have synthesized two homologous series viz. 2-((3-phenyl allylidene) amino) phenyl 4-((4-n-alkoxy benzylidene) amino) benzoate (series-1) and 4-((2-((3-phenyl allylidene) amino) phenoxy) carbonyl) phenyl-4-n-alkoxy benzoate (series-2). Both the series are differing with respect to first linking group. In series-1, comp.C₄–C₁₈ shows nematic as well as smectic phase while in series-2, comp.C₁₀–C₁₆ shows smectic and nematic phase while comp.C₄–C₁₈ shows only nematic phase.

KEYWORDS:

• Hockey-stick
• liquid crystals
• nematic
• smectic

Acknowledgments

Authors acknowledge thanks to Dr. R. R. Shah, principal and management of K. K. Shah Jarodwala Maninagar Science College, Ahmedabad. Authors are also thankful to NFDD Centre for providing analytical and spectral services.