Synthesis and Band Gap Analysis of Meso-Arylporphyrins Containing Exclusively Electron Donating or Withdrawing Groups

Abstract

Tetra-aryl substituted A4-type porphyrins (TP, TD, TA) and trans-A2B2 porphyrins (DDP1, AAP1) with electron- donating or withdrawing groups were synthesized. The band gap energy of those porphyrins was calculated from their UV-Vis spectra and CV data. With an electron-withdrawing group, the band gap energy of porphyrin TA increased via the LUMO energy up. Meanwhile, the introduction of an electron-donating group decreased the band gap of porphyrin by HOMO level up as as in the case of porphyrin TD. The band gap (2.19-2.28 eV) of metalloporphyrin PP-Ni was greater than those (1.81-2.06 eV) of non-metalloporphyrins PP due to the LUMO level up.