1,4-Diaryl and Schiff's base [1,2,3]-triazole derivative liquid crystalline compounds

Regioselective synthesis of 1,2,3]-triazoles based on the 'click-reaction', involving the Cu(I)-catalysed 1,3-dipolar cycloaddition of aryl azide to terminal arylacetylenes, was successfully employed in the preparation of two series of non-linear mesogens, based on 1,4-diaryl-1,2,3]-triazole (Ia-e) and with Schiff's base units (IIa-c). Their mesophases were characterized by polarizing optical microscopy and differential scanning calorimetry. All final compounds exhibited preferentially the SmC phase. In addition, compounds of series I showed weak blue fluorescence in solution (λ_{max. em.} = 380-386 nm) with poor quantum yields and a Stokes shift of around 90 nm.