Abstract
The phase behaviour of equimolar mixtures of 4-octyloxybenzoic acid, OOBA, and either 1-(4-butylazobenzene-4'-oxy)-6-(4-oxypyridine)pentane, BuABO5OPyr, or 1-(4-butylazobenzene-4'-oxy)-6-(4-oxypyridine)hexane, BuABO6OPyr, is reported. OOBA exhibits enantiotropic smectic C and nematic phases, whereas BuABO5OPyr and BuABO6OPyr are not liquid crystalline. Both the OOBA/BuABO5OPyr and OOBA/BuABO6OPyr equimolar mixtures show an enantiotropic smectic A phase identified using Xray diffraction and polarised light microscopy. The liquid crystallinty of the mixtures is attributed, in part, to the formation of a 1:1 hydrogen-bonded complex between OOBA and either BuABO5OPyr or BuA-BO60Pyr. Differences in the transitional properties of the mixtures are accounted for in terms of the average shapes of these 1:1 complexes. Temperature dependent FTIR spectroscopy shows, however, that the formation of the complex is not quantitative in the mixtures but instead a complex mixture exists over the complete temperature range studied, involving the 1:1 complex, both cyclic and open acid dimers, free acid and hence, free BuABOnOPyr molecules. (C) 2015 Elsevier B.V. All rights reserved.
Original language | English |
---|---|
Pages (from-to) | 429-437 |
Number of pages | 9 |
Journal | Journal of Molecular Structure |
Volume | 1100 |
Early online date | 1 Aug 2015 |
DOIs | |
Publication status | Published - 15 Nov 2015 |
Keywords
- Liquid crystal dimers
- Hydrogen bonding
- Temperature variable FTIR
- Supramolecular liquid crystals
- Low molar-mass
- Side-chain
- Pyridyl moieties
- Carboxylic-acid
- Molecular-orientation
- Amorphous polymers
- FTIR spectroscopy
- IR-spectra
- Oligomers
- Mixtures
Fingerprint
Dive into the research topics of 'The role of hydrogen bonding in the phase behaviour of supramolecular liquid crystal dimers'. Together they form a unique fingerprint.Profiles
-
Alfonso Martinez-Felipe
- Engineering, Engineering - Senior Lecturer
- Centre for Energy Transition
Person: Academic