Synthesis of Some Novel Aromatic Alkynyl Silanes: Mesomorphic Characterization of Ethynyl-Substituted Rod-Shaped Molecules

Abstract

The synthesis and characterization of 10 new rod-shaped substituted benzoates possessing the 4-(2-trimethylsilyl)ethynyl group in terminal phenyl position is reported employing the simple and efficient Sonogashira cross-coupling and DCC esterification. 4′-Dodecylbiphenyl-4-carboxylic(2-trimethylsilylethynyl)-phenyl ester (3i), 4-(4′-hexadecyloxybenzyloxy) carboxylic-4-trimethylsilanylethynyl-phenyl ester (3j), and 1,4-bis(4-(pentyloxy)phenyl)buta-1,3-diyne (7) compounds were evaluated for liquid crystal property.

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Keywords:

• Liquid crystals
• Smectic mesophase
• Sonogashira coupling
• 2-trime- thylsilylethynyl

Acknowledgments

We are thankful to Mrs. K. N. Vasudha, RRI, Bengaluru, for thermal and X-ray analysis. Grateful thanks to the NMR Research Center, Indian Institute of Science, for NMR spectral analysis. Financial support by the University Grants Commission and Department of Science and Technology, New Delhi, India, is gratefully acknowledged.