Aggregation behavior of 5,10,15-tris(pentafluorophenyl)corrole (F15TPC), 5,10,15,20-tetra(pentafluoroph-enyl)porphyrin (F20TPP), and their copper complexes in DCM solution were investigated by using UV-Vis spectro-scopic method. F20TPP and F20TPPCu exhibited strong π-π stacking interactions in DCM, and the intermolecular dimerization constants turned out to be 1.82 × 103 and 17.2 × 103 L·mol-1 respectively. However, extinction coefficients of F15TPC and F15TPCCu at soret band remained unchanged with increasing in their concentrations from 1.0 to 40.0 μmol·L-1, indicating they remained monomeric in DCM solution. Based on DFT calculation and the π-π stacking geometries observed in crystal structures of metal octaethylcorrole complexes, destroy of π-π interactions in F15TPC and F15TPCCu may be understood by the electrostatic potential surfaces (EPS) features of the molecules and steric repulsions caused by the introducing of three phenyl at the meso- positions of corrole macrocycle.
10-(2-Hydroxylphenyl)-5,15-bis(pentafluorophenyl) corrole([STHZ]1) was found to have a remarkable photocytotoxicity on nasopharyngeal carcinoma(NPC) cell line(Chang C.K.et al.,Proc SPIE,2006,Vol.6139,p268).To explore the heavy-atom effect on corrole photosensitizer,an exact analogue of corole [STHZ]1[STBZ] with the modification of two heavy iodine atoms on its 10-phenyl group,10-(2-hydroxyl-3,5-diiodophenyl)-5,15-bis(pentafluorophenyl)corrole(2),were synthesized.Surprisingly,the photocytoxicity of corrole 2 on NPC cell dropped sharply as compared to corole 1.It exhibited no significant PDT cytotoxicity even if its concentration reached 2 μmol/L.This may be caused by the lowering of its singlet oxygen quantum yield in PDT, although the intersystem crossing of corrole 2 could be enhanced by iodine heavy-atom effect as indicated by the strong decrease of its fluorescence emission.
