The effect of benzene ring substituent at different position of main ligand on electronic structure and photophysical properties of a series of iridium(III) complexes

The electronic structure and photophysical properties of a series of iridium(III) complexes have been theoretically explored by DFT/TDDFT calculations. Ionization potential, electron affinities, and reorganization energy have been calculated to evaluate the charge transfer and balance properties between hole and electron for the three complexes. The lowest lying absorption of 3 is obviously blue-shifted in contrast to those of 1 and 2, which is consistent with the variation of the energy gap between of LUMO and HOMO values. The calculated lowest energy emissions of complexes 1, 2 and 3 are located at 607, 634 and 698 nm, respectively.