Study and Characterization of Double Hydrogen-Bonded Liquid Crystals Comprising p-n Alkoxy Benzoic Acids with Azelaic and Dodecane Dicarboxlic Acids

Two series of double hydrogen-bonded liquid-crystalline complexes have been designed and synthesized. Dodecane dicarboxlic acid (DDC) and azelaic dicarboxlic acid (AC) belong to the same family of dicarboxlic acids having similar structural properties but with increasing H-C-H spacer groups. A succe...

Full description

Saved in:
Bibliographic Details
Published in:Molecular Crystals and Liquid Crystals 2011-04, Vol.537 (1), p.36-50
Main Authors: Subhapriya, P., Vijayakumar, V. N., Mohan, M. L. N. Madhu, Vijayanand, P. S.
Format: Article
Language:English
Subjects:
Acids
Benzoic acid
Carbon
Chemical synthesis
Colorimetry
Crystals
Dodecane
FTIR
hydrogen bonded liquid crystal
Hydrogen bonds
Liquid crystals
Microscopy
NMR
Nuclear magnetic resonance
Optical microscopy
optical textures
Physical properties
Spacers
Spectrum analysis
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Two series of double hydrogen-bonded liquid-crystalline complexes have been designed and synthesized. Dodecane dicarboxlic acid (DDC) and azelaic dicarboxlic acid (AC) belong to the same family of dicarboxlic acids having similar structural properties but with increasing H-C-H spacer groups. A successful attempt has been made to form hydrogen bonding between DDC and AC with p-n-alkyloxy benzoic acids (nOBA) by varying the respective alkyloxy carbon number and the physical properties exhibited by the individual series. The first series comprises DDC and p-n-alkyloxy benzoic acids (nOBA) and the other series is formed between AC and nOBA, where n represents the alkyloxy carbon numbers from 5 to 12 (except 6). These two homologous series are analyzed by polarizing optical microscopy (POM), differential scanning colorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and proton nuclear magnetic resonance (NMR) studies. The formation of an inter-hydrogen bond is evinced through FTIR and 1 H NMR. An interesting feature of DDC + nOBA homologues series is the stabilization of the higher order smectic C phase with increasing chain length. In the AC + nOBA homologues series a smectic G phase is induced with the increment of alkyloxy number. Phase diagrams of the above complexes are computed and compared. An even-odd effect in both series is discussed with respect to the enthalpy values at the isotropic to nematic phase.
ISSN:1542-1406
1563-5287
1527-1943
DOI:10.1080/15421406.2011.556429