Title:	Unusual odd-even effects depending on the monomer chain length in nematic liquid crystals made of rod-like dimers
Authors:	Kundu, Brindaban Pal, Santanu Kumar Kumar, Sandeep Pratibha, R. Madhusudana, N.V.
Keywords:	Condensed matter: structural, mechanical & thermal Soft matter, liquids and polymers
Issue Date:	13-Feb-2009
Publisher:	IOP Publishing Ltd.
Citation:	Europhysics Letters, 2009, Vol. 85(3), p36002
Abstract:	We report physical studies on the nematic phase exhibited by five members of a homologous series of symmetric dimers which have cyanobiphenyl end groups and, a disulphide bridging group in the spacer. All of them have rod-like conformations in the nematic phase, but unusually, the nematic-isotropic transition temperature, the birefringence and the dielectric anisotropy exhibit "odd-even" effects depending on the number of carbon atoms in the alkyl chain of a monomeric moiety. Further, the lowest "even" homologue exhibits a nematic-nematic transition. We argue that these phenomena arise from the relatively facile rotational fluctuations of the two monomeric moieties around the central S-S bond, whose orientation with respect to the long molecular axis changes between the "even" and "odd" members.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/3778
ISSN:	0295-5075 1286-4854 (Online)
Alternative Location:	http://dx.doi.org/10.1209/0295-5075/85/36002
Copyright:	2009 IOP Publishing Ltd.
Appears in Collections:	Research Papers (SCM)

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