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

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).