2007 Fiscal Year Final Research Report Summary
Spectroscopic study on excitonic interactions in hydrogen-bonded dusters in the gas phase
| Project/Area Number |
18350013
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | Kyushu University |
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Principal Investigator |
SEKIIYA Hiroshi Kyushu University, Department of Chemistry, Faculty of Scienoes, Professor (90154658)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANO Haruyuki KYUSHU UNIVERSITY, Department of Chemistry, Faculty of Scienoes, Professor (90251363)
SAKOTA Kenji KYUSHU UNIVERSITY, Department of Chemistry, Faculty of Scienoes, Assistant (80346767)
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| Project Period (FY) |
2006 – 2007
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| Keywords | excitonic interaction / excited-state dynamics / supersonic jet / hydrogen bond / proton transfer / electronic spectrum / fluorescence / tunneling effect |
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| Research Abstract |
It is known that there are two types of excitonic interaction in Frenkel type: One is strong coupling case and the other is weak coupling case. The excitonic interaction in planar hydrogen-bonded dimer and clusters has not been clarified. We have investigated excitonic interactions in the hydrogen-bonded clusters in the gas phase with laser spectroscopic methods. The molecular systems we studied are 7-azaindole dime substituted 7-azaindole dimers (7AI_2), and 1-azacarbazole dimer (1AC_2). We have measured the electronic spectra of isotopomers, undeuterated (hh), one of the NH groups is deuterated (hd) , and the two NH groups are deuterated (dd). In the case of 7AI_2hd the excitation is completely localized on one monomer unit (h *d or hd*) in the lowest excited electronic sate (S_1), indicating that the 7AI_2 in the S_1 state should be classified as a weak coupling case of the exciton theory. The splitting of the zero-point level due to excitonic interaction has been determined to be〜2 cm^<-1>. The excitonic splittings of 4-chloro-7-azaindole dimer and 4-dimethylamino-7-azaindole dimer are predicted to be similar values as 7AI_2. On the other hand, the excitation is not completely localized on one monomer moiety in 1AC_2-hd The difference between 7Al_2 and 1AC_2is due to smaller excitonic splitting in the S_1 state of 1AC_2.
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