TY - JOUR
T1 - Theoretical study on excitation dynamics of 5-dibenzosuberene and its derivatives
AU - Nakai, Hiromi
AU - Baba, Takeshi
N1 - Funding Information:
The authors are grateful to Prof. Hiroaki Takahashi for valuable discussion and comments. Part of the calculations was performed at the Research Center for Computational Science (RCCS) of the Okazaki National Research Institutes and the Media Network Center (MNC) of Waseda University. This study was partially supported by a Grant-in-Aid for Young Scientists (A) ‘KAKENHI 14703005’ from the Japanese Society for the Promotion of Science (JSPS), the Joint Studies Program (2002–2004) of the Institute for Molecular Science, a NAREGI Nano-Science Project of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), and the 21st century Center Of Excellence (21COE) ‘Practical Nano-Chemistry’ from MEXT.
PY - 2005/2/14
Y1 - 2005/2/14
N2 - The present study theoretically investigated structures and dynamics of 5-dibenzosuberene (DBCH), 5-dibenzosuberenol (DBCH-5-ol), and 5-dibenzosuberenone (DBCH-5-one) in the excited states, in order to clarify specific behavior of transient species of DBCH-5-one in picosecond time region. The theoretical results confirm that the transient species observed in picosecond time-resolved absorption spectra of DBCH and DBCH-5-ol correspond to the S1 state and those in nanosecond ones to the T1 state. On the other hand, both picosecond and nanosecond transient species of DBCH-5-one are shown to be the T1 state, which means that the lifetime of S1 transient species is shorter than the picosecond order. Furthermore, the short lifetime of the S1 transition species is found to be due to large transition probability of S1→T1 intersystem crossing. Since the S1 state has n-π* character and the T1 state π-π* one, the spin-orbit coupling and, therefore, the transition probability between the S1 and T1 states are large, which corresponds to El-Sayed rule.
AB - The present study theoretically investigated structures and dynamics of 5-dibenzosuberene (DBCH), 5-dibenzosuberenol (DBCH-5-ol), and 5-dibenzosuberenone (DBCH-5-one) in the excited states, in order to clarify specific behavior of transient species of DBCH-5-one in picosecond time region. The theoretical results confirm that the transient species observed in picosecond time-resolved absorption spectra of DBCH and DBCH-5-ol correspond to the S1 state and those in nanosecond ones to the T1 state. On the other hand, both picosecond and nanosecond transient species of DBCH-5-one are shown to be the T1 state, which means that the lifetime of S1 transient species is shorter than the picosecond order. Furthermore, the short lifetime of the S1 transition species is found to be due to large transition probability of S1→T1 intersystem crossing. Since the S1 state has n-π* character and the T1 state π-π* one, the spin-orbit coupling and, therefore, the transition probability between the S1 and T1 states are large, which corresponds to El-Sayed rule.
KW - Ab initio study
KW - Dibenzocycloheptene
KW - Excitation dynamics
KW - Spin-orbit coupling
KW - Time-resolved absorption spectroscopy
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U2 - 10.1016/j.molstruc.2004.11.009
DO - 10.1016/j.molstruc.2004.11.009
M3 - Article
AN - SCOPUS:12344318192
VL - 735-736
SP - 211
EP - 216
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
SN - 0022-2860
IS - SPEC. ISS.
ER -