Jump to main content
Jump to site search


Structure and molecular packing in smectic BCr and Ad phases of Schiff base liquid crystal compounds through the analyses of layer spacing, entropy and crystal structure

Author affiliations

Abstract

Single-crystal structural analyses and heat capacity measurements were performed on two Schiff base liquid crystal compounds, 5CBAA (4-chlorobenzylidene-4′-pentyloxyaniline) and 5ABCA (4-pentyloxybenzylidene-4′-chloroaniline). The alkyloxy-chain of a 5CBAA molecule was conformationally ordered in the crystal at room temperature. While that of 5ABCA was partially disordered in the room temperature phase but ordered in a low-temperature phase at 100 K. The structural phase transition involving the disordering of the conformation was observed at 107 K in the heat capacity of 5ABCA. Both compounds showed two liquid crystalline phases, SmBCr and SmAd. The net entropy change associated with the chain disordering was essentially the same in them despite the difference in the orientation of their central –CH[double bond, length as m-dash]N– moiety. The layer-spacings of SmBCr and SmAd phases were analyzed for their chain-length dependence in both series of mesogens (nCBAA and nABCA), as well as in the case of nBBAA (4-bromobenzylidene-4′-alkyloxyaniline). The results reveal that these smectic structures are composed of alternately stacked core- and chain-layers with an antiparallel arrangement of cores and a bent-form of molecules.

Graphical abstract: Structure and molecular packing in smectic BCr and Ad phases of Schiff base liquid crystal compounds through the analyses of layer spacing, entropy and crystal structure

Back to tab navigation

Supplementary files

Publication details

The article was received on 09 Jun 2017, accepted on 03 Jul 2017 and first published on 03 Jul 2017


Article type: Paper
DOI: 10.1039/C7CP03863A
Citation: Phys. Chem. Chem. Phys., 2017, Advance Article
  •   Request permissions

    Structure and molecular packing in smectic BCr and Ad phases of Schiff base liquid crystal compounds through the analyses of layer spacing, entropy and crystal structure

    Y. Yamamura, T. Murakoshi, S. Iwagaki, N. Osiecka, H. Saitoh, M. Hishida, Z. Galewski, M. Massalska-Arodź and K. Saito, Phys. Chem. Chem. Phys., 2017, Advance Article , DOI: 10.1039/C7CP03863A

Search articles by author

Spotlight

Advertisements