1992 Fiscal Year Final Research Report Summary
Theoretical Studies on the Dynamics of Photochemical Processes in Solutions
| Project/Area Number |
03453008
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
物理化学一般
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
KATO Shigeki Kyoto Univ., Science, Professor, 理学部, 教授 (20113425)
|
|---|
| Project Period (FY) |
1991 – 1992
|
| Keywords | Solution Phase Reaction / Photochemical Processes / Molecular Theory / Electron Transfer / Norrish type II Reaction / Molecular Dynamics / Free Energy Surface |
|---|
| Research Abstract |
This research started in 1991 with the aim to provide realistic molecular models for the dynamics of photochemical processes in solutions. We have carried out the molecular dynamics (MD) calculations for the Norrish type II reaction and the photo-induced charge transfer state formation reaction of 4-(N,N-dimethylamino)benzonitrile(DMABN). For the Norrish type II reaction, the mechanism of electronic relaxation of 1,4-diradical intermediate derived from butanal was examined. The ab initio calculations were performed to obtaine the potential energy surfaces of singlet and triplet diradicals and the spin-orbit coupling element between them. The MD calculations for the diradical in methanol solution were carried out to obtain the rate constant for the triplet-singlet transition. The results were consistent with the experimental findings. For the photo-induced electron transfer reaction of DMABN, we derived a new reaction surface Hamiltonian for the torsional mode of dimethylamino group and the solvation coordinate by assuming the harmonic bath model for the solvent motions. The MD calculations were utilized to obtain various quantities included in the Hamiltonian such as the free energy surface, the effective mass for the solvation coordinate and the friction kernel for the solvent relaxation. The stochastic trajectory calculations were carried out to obtain the reaction rate.
|
