Development of iridium porphyrin arrays by axial coordination trough N-bidentate ligand: Synthesis and evaluation of the optical, electrochemical and thermal properties

Abstract

Several organic compounds have been used in optoelectronics devices; porphyrins, due to their interesting optical and electronic properties, have shown an attractive potential to be used on molecular electronics. Among other advantages, porphyrins easily coordinate with several metal ions, which allows the assembly with peripheral or axial ligands introducing new properties to the supramolecular porphyrin. In this work, a new metalloporphyrin system with 5,10,15,20-(tetra-p-tolyl)porphyrin (ttp) and iridium(III) where 4,4’-bipyridine (bpy) coordinate in the axial positions was successfully synthetized, through the formation of “shish kebab” structures. This new compound was characterized through ultraviolet-visible, proton nuclear magnetic resonance, Fourier-transform infrared and Raman spectroscopies, thermogravimetry, differential scanning calorimeter and cyclic voltammetry. The introduction of the bpy on the metalloporphyrin moiety exhibited important influence on the optical, thermal and electrochemical properties.