摘要
We studied the excitation energies of zinc porphyrin(ZnP) and zinc porphyrin analogues(ZnP-R) with long-range corrected(LC) density functional theory. We compared three recent LC functionals, wB97XD, CAM-B3LYP, LC-wPBE and functionals B3LYP with the experiments. It was lbund that the low energy excitation is well predicted for ZnP with the LC-wPBE functional based on 6-31G(d) basis set. Excited-state geometry optimiza- tions lbr all the compounds were carried out. It was shown that upon the photo-excitation nearly 1 e transferred to the acceptor unit[dodecafluorosubphthalocyanine, SubPc(F)12] and a highly polarized state formed in compound 5. But after the relaxation of the first excited state, the electron on the acceptor went back to the ZnP a little and then shifted from ZnP to the donor segment[bis(4-hexylphenyl)amino] partially. The computed excited-state radiative lifetime(r) for compound 5 is 943 μs, which shows a reasonable agreement with the experimental observation. According to the long-lived exciton in strong push-pull compound 5, we proposed that electron injection to semiconductor might occur alter vibrational relaxation of excited state.
We studied the excitation energies of zinc porphyrin(ZnP) and zinc porphyrin analogues(ZnP-R) with long-range corrected(LC) density functional theory. We compared three recent LC functionals, wB97XD, CAM-B3LYP, LC-wPBE and functionals B3LYP with the experiments. It was lbund that the low energy excitation is well predicted for ZnP with the LC-wPBE functional based on 6-31G(d) basis set. Excited-state geometry optimiza- tions lbr all the compounds were carried out. It was shown that upon the photo-excitation nearly 1 e transferred to the acceptor unit[dodecafluorosubphthalocyanine, SubPc(F)12] and a highly polarized state formed in compound 5. But after the relaxation of the first excited state, the electron on the acceptor went back to the ZnP a little and then shifted from ZnP to the donor segment[bis(4-hexylphenyl)amino] partially. The computed excited-state radiative lifetime(r) for compound 5 is 943 μs, which shows a reasonable agreement with the experimental observation. According to the long-lived exciton in strong push-pull compound 5, we proposed that electron injection to semiconductor might occur alter vibrational relaxation of excited state.
基金
Supported by the National Natural Science Foundation of China(No.11179033), the Program for New Century Excellent Talents in University of China(No.NCET- 10-0011), the Beij ing Natural Science Foundation, China(N o.2132017 ) and Program for the Top Young Talents of Higher Learning Institutions of B eijing Municipality China.