Abstract
The synthesis and characterisation of new non-symmetric 2,5-bis(4-alkylphenylethynyl)thiophenes are described. Phase transition properties of these non-symmetric homologues are compared to those of the corresponding symmetric analogues. Furthermore, optical, dielectric and elastic data of investigated compounds and nematic mixture are provided. Compounds are characterised by 1H NMR spectroscopy and mass spectrometry (electron ionization) analysis. They show an enantiotropic nematic behaviour in broad temperature ranges, confirmed by a polarising thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached, showing a great synthetic versatility of the thiophene ring substitution. Synthesised compounds stand as promising components of highly birefringent liquid crystalline mixtures.