Progress on ligands effects in porphyrin-based molecules in benzene solvent for photodynamic therapy applications

Density Functional Theory (DFT) calculations are carried out to investigate the ligands effects on porphyrin-based molecule in benzene solvent environment. Benzene solvent is modeled by PCM Tomasi. We are motivated to study the alternation of electronic and geometric structure of porphyrin-based molecule in the presence of ligands for achieving theoretical explanation about ligand porphyrin-based behaviours. We aim to investigate the ligands effect on the groundstate electronic structure of porphyrin-based molecules. This investigation will lead us in better understanding on characteristic of porphyrin-based molecule as photosensitizer in benzene solvent environment. We perform the electronic structure calculation of ZnP, ZnTPP, ZnTBP, H2TPP and H2TBP in the ground state. The results show that ligands distortion induces the point group symmetry of ZnTBP, ZnTPP, H
2
TBP and H
2
TPP belong to the trivial point group (C
1
) in benzene environment. Tetrabenzo ligand distortions significantly change the Zn-N bond of ZnP. The energy difference between HOMO and HOMO-1 is increasing in the present of ligand. We also report that benzene solvent has only significant contribution to the alternation of E
Δ
of porphyrin-based molecules.