| Project/Area Number |
08640642
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Physical chemistry
|
|---|
| Research Institution | Japan Advanced Institute of Science and Technology |
|---|
Principal Investigator |
UMEMOTO Hironobu Japan Advanced Institute of Science and Technology, School of Materials Science, Associate Professor, 材料科学研究科, 助教授 (80167288)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Project Status |
Completed (Fiscal Year 1997)
|
| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
|---|
| Keywords | nitric oxide / nitrous oxide / two-photon dissociation / action spectra / Doppler profile / 前期解離 / 亜酸化窒素 |
|---|
| Research Abstract |
Two-photon dissociation processes of nitric oxide and nitrous oxide were studied by using pulsed laser techniques.
N_2O was two-photon photolyzed between 235 and 240 nm under beam conditions. N (^2D), N (^2P), and NO (v=1) could be detected as products by a resonance-enhanced multiphoton ionization technique combined with a time-of-flight mass'spectrometric technique. The Doppler profile measurements of N (^2D) and N (^2P) were also carried out. From the widths of the Doppler profiles, it is possible to determined the maximum velocities of these species in the laboratory frame. Comparison of these velocities with those expected from the exothermicities of the photodissociation processes showed that these species are formed in the two-photon dissociation of N_2O.Dissociation of the three-photon super excited states to these species can be ignored. The yields of N (^2D), N (^2P), and NO (v=1) as well as that of parent N_2O^+ ions were measured as a function of the wavenumber of the excitation laser. Vibrational structures attributable to 3psigma ^1II-X^1SIGMA^+ transition could be observed. Excitation to the 2^1_ (SIGMA^+) state was found to promote the dissociation to neutral species compared to the excitation to other vibrational levels such as the 1^1_ and 2^1_ (DELTA) states. This suggests that the predissociation proceeds via a dissociative A'state in the C_S symmetry. One of the strongest candidates is the 5^1A'state.
In the two-photon dissociation of NO around 275 nm, N (^2D) as well as O (^3P) could be detected as products. N (^4S) could not be detected as far as we tried. The action spectra of N (^2D) and O (^3P) were compared. They were similar suggesting that the production of N (^2D) and O (^3P) should be the main exit channe.
|
