Analysis of the reflection spectra of chiral smectic liquid crystal phases is used to provide detailed information on physical parameters, including refractive indices, helicoidal pitch and tilt angle. Numerical models of the antiferroelectric and ferroelectric phases are constructed, based on a 4 × 4 matrix technique, and a downhill simplex algorithm is employed to fit the model to reflection spectra measured from free-standing films of the materials of interest. The temperature dependence of the refractive indices, dispersion, tilt angle and pitch are reported for three different liquid crystalline materials. The accuracy of the fitting method is around 1%, better than the experimental error, and this is confirmed by comparison of the parameters determined by the fitting program with those measured by independent methods.

The synthesis of a novel ferroelectric alkoxythiophene-containing liquid crystal is described together with the mesophase morphology of the material. The alkoxythiophene unit is introduced by a highly efficient ring closure of an appropriate gamma -ketoester using Lawesson's reagent as the sulfurating agent. Our new cyclization methodology represents the most efficient synthetic pathway for the synthesis of this unit.

Several esters have been synthesised that exhibit the antiferroelectric smectic C phase. The core structures, like virtually all antiferroelectric materials, are very similar to that of MHPOBC. Lateral fluoro substituents have been used to reduce melting points and to investigate their effect on mesomorphic properties, spontaneous polarisation and tilt angle. A new device format reported by Lagerwall requires antiferroelectric liquid crystals with a 450 degrees tilt angle. Novel antiferroelectric materials were prepared with fluoro substituents in lateral positions and in a terminal chain to provide low melting points, high antiferroelectric phase stability, high spontaneous polarisation and tilt angles of up to 45 degrees. The synthetic routes to the novel materials are discussed, and the transition temperatures, tilt angles and spontaneous polarisations are compared to those of known materials.

A variety of alkoxythiophenes have been synthesized that represent ideal subunits for the synthesis of a new class of thermotropic liquid crystals via palladium-catalyzed cross-coupling reactions and organometallic derivatization. The methodology used represents the first highly efficient synthesis of alkoxythiophenes unlike previous pathways that have presented serious synthetic difficulties when the alkoxy chain consisted of more than four carbon atoms. The scope of the new procedure (relative to liquid crystalline intermediates) is presented and is compared and contrasted with the current literature.