TY - JOUR
T1 - Electronic structure of the lowest excited triplet state of 5,12-naphthacenequinone
AU - Shimokage, Takuji
AU - Ikoma, Tadaaki
AU - Akiyama, Kimio
AU - Tero-Kubota, Shozo
N1 - Funding Information:
We are grateful to Professor H. Shizuka and Dr M. Yamaji, Gunma University, for their helpful discussion. The present research was supported in part by Grants-in-Aid for Scientific Research (No. 11440210 and 12740310) from the Ministry of Education, Science, Sports and Culture, Japan.
PY - 2002
Y1 - 2002
N2 - Continuous-wave time-resolved EPR (cw-TREPR) and pulsed electron nuclear double resonance (ENDOR) studies have been carried out to clarify the electronic structure of the lowest excited triplet (T1) state of 5,12-naphthacenequinone (5,12-NpQ) as well as 1,4-anthraquinone (1,4-AQ) and 6,13-pentacenequinone (6,13-PeQ). The T1 energy level and the D value of the zero-field splitting (ZFS) parameters only slightly decreased with the increasing π-conjugated system. The T1 states of these linear para-acenequinones were assigned to the ππ* character. In triplet 5,12-naphthacenequinone, more than 80% of the unpaired electron spins are localized on the naphthalene aromatic sub-system.
AB - Continuous-wave time-resolved EPR (cw-TREPR) and pulsed electron nuclear double resonance (ENDOR) studies have been carried out to clarify the electronic structure of the lowest excited triplet (T1) state of 5,12-naphthacenequinone (5,12-NpQ) as well as 1,4-anthraquinone (1,4-AQ) and 6,13-pentacenequinone (6,13-PeQ). The T1 energy level and the D value of the zero-field splitting (ZFS) parameters only slightly decreased with the increasing π-conjugated system. The T1 states of these linear para-acenequinones were assigned to the ππ* character. In triplet 5,12-naphthacenequinone, more than 80% of the unpaired electron spins are localized on the naphthalene aromatic sub-system.
KW - Excited triplet states
KW - Naphthacenequinone
KW - Pulsed ENDOR
KW - Time-resolved EPR
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U2 - 10.1016/S1386-1425(01)00710-7
DO - 10.1016/S1386-1425(01)00710-7
M3 - Article
C2 - 11993468
AN - SCOPUS:0036005829
VL - 58
SP - 1201
EP - 1208
JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
SN - 1386-1425
IS - 6
ER -