Tuning the mesogenic properties of 5-alkoxy-2-(4-alkoxyphenyl)pyrimidine liquid crystals: the effect of a phenoxy end-group in two sterically equivalent series |
| |
Authors: | Matthew Thompson Carolyn Carkner Adrian Bailey Nicholas J. Mosey Nadia Kapernaum |
| |
Affiliation: | 1. Chemistry Department, Queen’s University, Kingston, ON, Canada;2. Institute of Physical Chemistry, Universit?t Stuttgart, Pfaffenwaldring 55, Stuttgart, Germany |
| |
Abstract: | Two sterically equivalent series of phenoxy-terminated 5-alkoxy-2-(4-alkoxyphenyl)pyrimidine liquid crystals were synthesised, and their mesogenic properties were characterised by polarised optical microscopy and differential scanning calorimetry (DSC). The phenoxy end-group causes a significant increase in melting point and inhibits – at least partially – the mesomorphism of these materials relative to the parent isomers; in most cases, the broad enantiotropic SmC phase formed by the parent isomers is suppressed by the addition of the phenoxy end-group. However, detailed analyses by small-angle X-ray scattering and monodomain 2D X-ray scattering suggest that these compounds form a SmA phase with a partially intercalated bilayer structure in which the phenoxy end-groups are nanosegregated. Such an intercalated bilayer structure might enable the tuning of smectogenic properties by appropriate substitution of the phenoxy end-groups. |
| |
Keywords: | smectic liquid crystal sterically equivalent series nanosegregation phenoxy end-group orientational order parameter effective length |
|
|