Project/Area Number |
61470015
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
構造化学
|
Research Institution | Mie University |
Principal Investigator |
KAWASAKI Masahiro Mie University, Faculty of Engineering, Associata Professor, 工学部, 助教授 (70110723)
|
Co-Investigator(Kenkyū-buntansha) |
SATO Hiroyasu Mie University, Faculty of Engineering, Professor, 工学部, 教授 (20029440)
|
Project Period (FY) |
1986 – 1987
|
Project Status |
Completed (Fiscal Year 1987)
|
Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥6,500,000 (Direct Cost: ¥6,500,000)
|
Keywords | Nitrogen dioxide / Carbon disulfide / Multiphoton / Photofragments / Angular distribution / Methyl nitrite / Translational energy / 多光子吸収 / 分解過程 / 真空紫外 / 有機金属 |
Research Abstract |
Two-photon dissociation of nitrogen dioxide and carbon disulfide at 308 nm has been studied by means of multiphoton ionization of photofragments. The angular distributions of fragments are well represented by a form of 1 + <beta>_2P_2(cos<theta> + <beta>_4P_4 (cos<theta>). Because the intermediate state of NO_2 (^2B_2) generated by the first one-photon process is dissociative, the coefficient <beta>_4 for the fourth degree Legendre polynomial is appreciable. The coefficient <beta>_4 for CS_2 is, however, not appreciable because the intermediate CS_2(^1B_2) state has a long fluorescence Iifetime. The angular distributions not only reveal the symmetry and lifetimes of the two-photon excited states of NO_2 and CS_2 but also information on the two-photon excitation process of these molecules. The photodissociation of methylnitrite in the molecular beam has been studied by laser irradiation at 308-364 nm. The translational energy distribution for the photofragment indicates that there are two distinct paths by which CH_3O and NO radicals are produced; one is a one-photon dissociation, and the other is a two-photon dissociation. The angular distribution of fragment intensities peaks in a direction orthogonal to the elctric vector of the photolysis light indicating that the transition moments for both the first and the second one-photon absorptions lie perpendicular to the O-N bond that breaks. Methyliodide ions prepared by two-photon resonant three-photon ionization via Rydberg states are photodissociated by a one-photon process to result in the formation of methyl fragment ions by laser irradiation at 335-403 nm. The parallel angular distrubutions of these fragment ions have rather small anisotropy parameters, suggesting that dissociation is predissociative via the A(^2E_<1/2>) state of CH_3I^+.
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