Synthesis and spectral characterisation of new amido-ether Schiff bases

Series of new compounds prepared by condensing the sodium salt of 4-[(4-methoxy-benzylidene)-amino]-phenol with chloroacetanilides carrying various substituents in different positions has been synthesised and characterised by UV–VIS, FTIR, MS, 1H and 13C NMR spectrometry. The effect of type and position of different substituents on thermal and on mesomorphic behaviour has been investigated by polarizing optical microscopy and differential scanning calorimetry studies. All compounds possess relatively high phase transition temperatures due to possibility of forming molecular associations and only the 2,4-substituted ones possess the liquid crystalline behaviour, namely the nematic phase.