TY - JOUR
T1 - Transient absorption, time-resolved fluorescence, and resonance Raman spectroscopic studies of Zr(TPP)2 and Zr(TPP)2(SbCl6)
AU - Lee, Minyung
AU - Song, Ok Keun
AU - Seo, Jung Chul
AU - Kim, Dongho
AU - Kim, Hee Joon
AU - Kim, Kimoon
PY - 1992
Y1 - 1992
N2 - Transient absorption, time-resolved fluorescence, and resonance Raman measurements are reported for Zr(TPP)2 and for the complex Zr(TPP)2(SbCl6) in which an electron is removed from the porphyrin π-system. The singlet excited-state lifetime of Zr(TPP)2 in dichloromethane was measured to be 1.9 ± 0.1 ns through the transient absorption technique and 1.95 ± 0.05 ns using the time-correlated single photon counting method, respectively. By contrast, the excited-state lifetime of Zr(TPP)2(SbCl6) was found to be 40 ± 10 ps, which is much shorter than that of the neutral species. The fast nonradiative deactivation of the cationic complex is likely caused by the rapid quenching of the initially excited doublet (π,π*) state via one or more of the states seen in the near-IR ground-state absorption spectrum. These low energy states correspond to transitions between the molecular orbitals derived from the a2u and a1u monomer orbitals through the π,π interaction of the two porphyrin subunits. In addition, resonance Raman spectroscopic data confirm that in Zr(TPP)2(SbCl6) one electron is removed from a dimer orbital derived from the monomer a2u orbital with a hole delocalized over the two porphyrin rings.
AB - Transient absorption, time-resolved fluorescence, and resonance Raman measurements are reported for Zr(TPP)2 and for the complex Zr(TPP)2(SbCl6) in which an electron is removed from the porphyrin π-system. The singlet excited-state lifetime of Zr(TPP)2 in dichloromethane was measured to be 1.9 ± 0.1 ns through the transient absorption technique and 1.95 ± 0.05 ns using the time-correlated single photon counting method, respectively. By contrast, the excited-state lifetime of Zr(TPP)2(SbCl6) was found to be 40 ± 10 ps, which is much shorter than that of the neutral species. The fast nonradiative deactivation of the cationic complex is likely caused by the rapid quenching of the initially excited doublet (π,π*) state via one or more of the states seen in the near-IR ground-state absorption spectrum. These low energy states correspond to transitions between the molecular orbitals derived from the a2u and a1u monomer orbitals through the π,π interaction of the two porphyrin subunits. In addition, resonance Raman spectroscopic data confirm that in Zr(TPP)2(SbCl6) one electron is removed from a dimer orbital derived from the monomer a2u orbital with a hole delocalized over the two porphyrin rings.
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U2 - 10.1021/j100200a031
DO - 10.1021/j100200a031
M3 - Article
AN - SCOPUS:0001742375
VL - 96
SP - 8374
EP - 8377
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
SN - 0022-3654
IS - 21
ER -