A Theoretical Study of the Reaction of O(³P) with Isobutene

Abstract

The reaction of O((3)P) with isobutene ((CH(3))(2)C=CH(2)) is investigated using the unrestricted second-order Møller-Plesset perturbation (UMP2) and complete basis set CBS-4M level methods. The minimum energy crossing point (MECP) between the singlet and triplet potential energy surfaces is located using the Newton-Lagrange method, and it is shown that the MECP plays a key role. The calculational results indicate that the site selectivity of the addition of O((3)P) to either carbon atom of the double bond of isobutene is weak, and the major product channels are CH(2)C(O)CH(3) + CH(3,) cis-/trans-CH(3)CHCHO + CH(3), (CH(3))(2)CCO + H(2), and CH(3)C(CH(2))(2) + OH, among which (CH(3))(2)CCO + H(2) is predicted to be the energetically most favorable one. The complex multichannel reaction mechanisms are revealed, and the observations in several recent experiments could be rationalized on the basis of the present calculations. The formation mechanisms of butenols are also discussed.

A Theoretical Study on Laser Cooling Feasibility of Group IVA Hydrides XH (X = Si, Ge, Sn, and Pb): The Role of Electronic State Crossing

“…The electronic state crossing between the B 2 − and A 2 states can lead to nonradiative transition (Wu et al, 2019), and may cause predissociation. This kind of electronic state crossing in a diatomic molecule will become potential energy surface intersections in the polyatomic cases involving multiple electronic states (Liu et al, 2003;Zhao et al, 2006). We find that the locations of crossing point between the B 2 − and A 2 states have the tendency of moving downwards from CH to SnH relative to the bottom of the corresponding A 2 state potential.…”

Untitled

“…The calculations of systems contain C, Si and H described by the standard 6-311G(d,p) basis set. Geometry optimization was performed utilized by the hybrid meta exchangecorrelation functional of Truhlar and Zhao (M06-2X) [17].A vibrational analysis was performed at each stationary point which confirmed its identity as an energy minimum.…”

The reliability of DFT methods to predict electronic structures and minimum energy crossing point for [FeIVO](OH)2 models: A comparison study with MCQDPT method

“…(The program can be obtained from the authors upon request.) The early version of this program has been used successfully to search the MECP of some nontransition metal reaction systems . Unfortunately, multireference perturbation theory lacks analytic gradients in GAMESS program.…”