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| Type |
Poster Presentation |
| Area |
Physical Chemistry |
| Room No. |
Exhibition Hall 2+3 |
| Time |
10월 20일 (금요일) 13:00~14:30 |
| Code |
PHYS.P-100 |
| Subject |
Conformation-dependent Photodissociation Dynamics of C2F4I2 in Solution |
| Authors |
Seongchul Park, Manho Lim*, Youngshang Pak
Department of Chemistry, Pusan National University, Korea
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| Abstract |
Photodissociation dynamics of CF2ICF2I in solution was investigated by probing the C–F stretching mode using femtosecond mid-IR pulse after excitation with a femtosecond 267-nm pulse. Dissociation of the first I atom was faster than 0.3 ps after the UV absorption. All of the resulting haloethyl radicals undergo the secondary dissociation with two time constants forming CF2CF2; the radical from the anti-CF2ICF2I, the major conformer with c.a. 80% population in CCl4 or in CH3CN solution dissociates with time constant of 165 ps or 42 ps, respectively. The radical from gauche-CF2ICF2I in CCl4 or in CH3CN solution dissociates with the time constant of 4.2 ns or 3.5 ns, respectively. The dissociation time is slower than 25 ps, time constant for the presumably major conformer in the gas phase. However, the estimated quantum yield (QY) for the secondary dissociation in solution was found to be 1, which is higher than the reported value much less than 1 in the gas phase. Previously the secondary dissociation QY in solution was reported to be 0.3 ~ 0.95. A photodissociation mechanism that explains the conformer-dependent dissociation rate of CF2ICF2I as well as its solvent-dependent dissociation rate is presented based on a potential energy surface of CF2ICF2 radical calculated with CASSCF.
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| E-mail |
papagenona@gmail.com |
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120th General Meeting of the KCS