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The synthesis and mesomorphic properties of liquid crystals with bulky terminal groups designed for bookshelf geometry ferroelectric mixtures

Radini, Ibrahim A.; Hird, Michael

Authors

Ibrahim A. Radini

Michael Hird M.Hird@hull.ac.uk



Abstract

The synthesis and mesomorphic properties of a systematic range of ortho difluoroterphenyls with a bulky terminal chain are detailed. The bulky terminal chain consists of either a tertiarybutyl group or a trimethylsilyl unit, each separated from the core by a short (dimethylene) chain, with the other terminal chain being either octyloxy or heptyl. The synthesis of the materials was affected efficiently using a combination of low temperature lithiations and palladium-catalysed cross-coupling reactions. Unusually for liquid crystals with bulky terminal chains, the smectic phase stability (particularly smectic C) is upheld by more than the nematic phase stability, and in most cases the smectic C phase stability is actually higher than comparable analogues with conventional unbranched terminal chains. It is postulated that the surprisingly high smectic C phase stability results from a phase separation effect due to the incompatibility of the spherical bulky group and the conventional unbranched terminal chain, hence implying that the smectic 'layers' are well defined, and such definition of the layers bodes well for bookshelf geometry in ferroelectric mixtures.

Citation

Radini, I. A., & Hird, M. (2009). The synthesis and mesomorphic properties of liquid crystals with bulky terminal groups designed for bookshelf geometry ferroelectric mixtures. Liquid crystals, 36(12), (1417-1430). doi:10.1080/02678290903268328. ISSN 0267-8292

Journal Article Type Article
Acceptance Date Aug 18, 2009
Online Publication Date Dec 14, 2009
Publication Date 2009-12
Publicly Available Date
Journal LIQUID CRYSTALS
Print ISSN 0267-8292
Electronic ISSN 1366-5855
Publisher Taylor & Francis
Peer Reviewed Peer Reviewed
Volume 36
Issue 12
Article Number PII 917778275
Pages 1417-1430
DOI https://doi.org/10.1080/02678290903268328
Keywords Tertiary butyl; Trimethylsilyl; Smectic C; Phase separation
Public URL https://hull-repository.worktribe.com/output/395909
Publisher URL https://www.tandfonline.com/doi/abs/10.1080/02678290903268328