what is the relation between the following atoms: 40X18 and 40Y 20?
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Answer:
The mechanism of the hydrogen abstraction reaction H2O2+OH→HO2+H2O in gas phase was revisited using density functional theory and other highly correlated wave function theories. We located two pathways for the reaction, both going through the same intermediate complex OH–H2O2, but via two distinct transition state structures that differ by the orientation of the hydroxyl hydrogen relative to the incipient hydroperoxy hydrogen. The first two excited states were calculated for selected points on the pathways. An avoided crossing between the two excited states was found on the product side of the barrier to H transfer on the ground state surface, near the transition states. We report on the calculation of the rate of the reaction in the gas phase for temperatures in the range of 250–500K. The findings suggest that the strong temperature dependence of the rate at high temperatures is due to reaction on the low-lying excited state surface over a barrier that is much larger than on the ground state surface.
ACKNOWLEDGMENTS
The authors gratefully acknowledge Dr. Karol Kowalski for his assistance in preparing the EOM-CCSD(T) calculations. This work was supported in part by the Office of Basic Energy Sciences of the Department of Energy (DOE), Chemical Sciences program [for two of the authors (B.G. and M.D.)] and in part by the U.S. Department of Energy’s Office