Mesomorphism of Binary Systems of Nonmesogenic Compounds

Abstract

Three binary systems, each consisting of two nonmesogenic compounds, viz. p-tolual-p-phenetidine (M.P. 108.5°C) [A] as the common component, and Methyl p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 119.0°C) [B₁], Ethyl-p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 94.0°C) [B₂], and n-Butyl p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 130.0°C) [B₃] as the second component, respectively, are studied with a view to understand the effect of terminal groups on nematic and/or smectic mesomorphism. Latent transition temperatures (LTT) of the constituent components A, B₁, B₂, and B₃ were determined by extrapolation. Binary system (A + B₁) induces a nematogenic mesophase while binary systems (A + B₂) and (A + B₃) both induce a smectic mesophase in addition to a nematic mesophase. Phase diagrams of the binary systems under investigation are plotted for the mole percent of component (A) versus the transition temperatures of each binary system as determined from polarizing optical microscopy. The texture of the nematic mesophase is of threaded type and that of the smectic mesophase is focal-conic fan shaped of the type smectic-A. Components A, B₁, B₂, and B₃ were prepared by established methods. Analytical data support the structure of molecules under investigation. Melting points of the constituent components match with data reported earlier.

Keywords:

• Mixed mesomorphism
• mixed melt
• meshophase
• smectic
• nematic

Acknowledgments

The authors give thanks to ex. Professor and Head, Dr. R. A. Vora, of the Department of Applied Chemistry, Faculty of Technology and Engineering, M. S. University of Baroda, Vadodara, for his valuable cooperation and suggestions in the work.