Synthesis, spectroscopy, surface photovoltage, and electrochemical properties of porphyrin compound liquid crystals

Abstract

Two series of porphyrin liquid crystalline compounds, meso-tetra-[(p-alkacyloxy-m-ethyloxy)phenyl]porphyrin ( TPAMEP ), and [5-(p-alkacyloxy) phenyl-10,15,20-tri-phenyl] porphyrin ( APTPP ) are synthesized and display a hexagonal columnar discotic columnar ( Col h ) phase. Their structure and properties were studied by elemental analysis, molar conductance, UV-visible and infrared spectra. Luminescence spectra of the compounds were discussed. Quantum yields of the Q band are in the region 0.007935-0.05847. The electrochemical studies show that the redox potentials do not change with the variation of the chain length. The surface photovoltage (SPV) response of the compounds was investigated by means of surface photovoltage spectroscopy (SPS) and field-induced surface photovoltage spectroscopy (FISPS), and the bands are analogous with the UV-visible absorption spectra.