Synthesis and self-assembly of photoresponsive and luminescent polycatenar liquid crystals incorporating an azobenzene unit interconnecting two 1,3,4-thiadiazoles†
Abstract
Novel polycatenar liquid crystals containing two 1,3,4-thiadiazole rings interconnected by an azobenzene central linkage have been synthesized and investigated by polarizing microscopy, DSC, X-ray scattering, SEM, UV-vis spectroscopy and photoluminescence measurements. These compounds can self-assemble into SmC, Colhex/p6mm and CubI/Pmn liquid crystalline phases in the bulk states and form multistimuli responsive organogels in organic solvents. They have reversible photoresponsive properties in solution, liquid crystalline states and gel states. They also show fluorescence emission with large Stokes shift in solution and binding selectivity to Cu2+ among a series of cations in CH3CN–CH2Cl2 solution.