811
Views
49
CrossRef citations to date
0
Altmetric
Invited Article

Non-conventional liquid crystals: synthesis and mesomorphism of non-symmetric trimers and tetramers derived from cholesterol

, , &
Pages 1563-1589 | Received 18 Jun 2011, Accepted 01 Aug 2011, Published online: 22 Nov 2011
 

Abstract

Non-conventional liquid crystals such as oligomers formed by covalent tethering of two to several anisometric (mesogenic) cores through flexible spacer(s) represent a fascinating and emerging class of functional soft materials. Over the last two decades or so, a variety of such motifs have been accomplished to illustrate their significance. This manuscript reviews certain specific examples of nonlinear and linear oligomers with a special attention to linear trimers and tetramers. Following this, the preparation and phase transitional behaviour of linear non-symmetric trimers and tetramers have been presented. Linear trimers have been made by covalently binding three different functional anisometric segments viz., promesogenic-optically active-cholesterol, promesogenic-naphthalene and photochromic-azobenzene cores, through two flexible spacers of varying length and parity. Tetramers have been synthesised by linking cholesterol, naphthalene, biphenyl (a promesogenic) and tolane (a half-disc) mesogenic moieties via three flexible spacers. The occurrence of mesomorphism in these supermolecules has been evidenced by optical textural pattern, calorimetric and powder X-ray diffraction studies. The phase transitional behaviour of these compounds has been compared with closely related known trimers and tetramers, which have in fact, served as reference/model for the substances synthesised in this study.

Acknowledgements

USH is grateful to the Department of Science and Technology (DST), Government of India, for sanctioning the project no. SR/WOS-A/CS-19/2010 under WOS-A scheme. The authors express their gratitude to Dr S. Krishna Prasad for many helpful discussions. They also thank Prof. K.A. Suresh for support and encouragement.

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 61.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.