Synthesis and Band Gap Analysis of Designed Porphyrin Derivatives Containing Electron Donating and Accepting Group

Abstract

Symmetric (DD, AA1-AA5) and non-symmetric (DA1) porphyrin derivatives were synthesized through McDonald coupling of bispyrrole 2D, 2A1-2A5 with the corresponding aldehyde 3 or diol 6 as a key step. The UV-Vis spectrum and CV of those porphyrins were measured and analyzed for band gap and HOMO-LUMO energy. With the electron withdrawing group, the band gap of porphyrins PP was increased and that of metalloporphyrin PP-M decreased. The HOMO level of PP and LUMO level of PP-M were more lowered than the LUMO of PP and the HOMO of PP-M, respectively. The LUMO level of all PP and PP-M was lower than that of P3HT (-2.80 eV) and all HOMO energy of PP and PP-M was higher than that of PCBM (-6.20 eV).