1988 Fiscal Year Final Research Report Summary
Chemical Behavior of Quasi-Stable Diradicals and Diradicaloids
| Project/Area Number |
61470007
|
|---|
| 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 | Osaka university |
|---|
Principal Investigator |
FUENO Takayuki Professor Osaka University, Faculty of Engineering Science, 基礎工学部, 教授 (60029387)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Kizashi Instructor Osaka University, Faculty of Engineering Science, 基礎工学部, 助手 (80029537)
OKUYAMA Tadashi Assoc. Prof. Osaka University, Faculty of Engineering Science, 基礎工学部, 助教授 (40029484)
|
|---|
| Project Period (FY) |
1986 – 1988
|
| Keywords | Diradicals / Imino radicals NH(^1delta,^3sigma^-) / Ethylnitrene / 1,2-Hydrogen migration / 1,3-Hydrogen migration / Intramolecular insertion / Reaction paths / 遷移状態 |
|---|
| Research Abstract |
Structures and kinetic behavior of various types of singlet and triplet diradicals and diradicaloids have been investigated both theoretically and experimentally. In theoretical studies, treatments of electronic structures and reaction paths by ab initio SCF and multireference CI computations were the primary concern. Experimental work was conducted exclusively in direct connection with the implications gained by theoretical computations. The most salient points of the outcumes of this project are itematized as follows:
1. Singlet monocentric diradical NH(^1delta) directly abstracts the hydrogen atom from paraffins in the gas phase. Theoretical computations show that the abstraction generally has low activation barriers of the order of 10-20 KJ/mol.
2. Reactions of NH^1delta) with NO in the gas phase is predicted to give N_2O as the principal product. The prediction was borne out experimentally. the quantum yield of N_2O being 0.70.
3. NH(^3sigma.^-), when allowed to react with NO, gives
… More
N_2 +OH as well. The branching ration for this channel is found to be 0.4 0.1 at 3500 K.
4. Reaction of NH(^3sigma^-) with O_2(^3sigmg_g^-) should first give an adduct HNO-O(^1A'). it is subject to the 1,3-hydrogen migration leading to NO-OH(^1A') followed by decomposition to NO + OH.
5. Intramolecular insertion of singlet ethylnitrene giving a ring compound, aziridine is predicted to be a low-barrier elementally reaction.
6. A dicentric diradical CH_2CH_2NH is the most stable in its singlet face-to face structure(^1FF). In the gas phase it should readily give CH_3CH=N・(^2A'), a direct precursor to CH_3CN and hcn, via the 1,2-hydrogen migration followed by the n-h bond scission.
7. The most stable form of the CH_2CH_2O diradical is ^1 (^1A'), which is liable to isomerize into CH_3CHO with an activation barrier of 27 kJ/mol.
8. SSO and S_3 are diradicaloids, which are more stable in the chain form than in the ringstructure, the energy differnces being 1.58 and 0.32 eV,respectively.
9. The disproportionation reaction OH + OH H_2O + O(^3P) proceeds via a hydrogen-bonded dimer OH・・・OH (^3sigma^-). The net barrier height is calculated to be 10 kJ/mol. The transition state theory reproduces the non-Arrhenius character of the bimolecular rate constants. Less
|
