title: Theoretical Investigation of the Reaction Mechanism of the Photoisomerization of 1,2-Dihydro-1,2-azaborine.
abstract: The photoisomerization of 1,2-dihydro-1,2-azaborine was investigated by high-level multireference ab initio and density functional theory calculations. The intermediates (IMs) and transition states (TSs) on the S(0) and S(1) states were optimized using the state-averaged complete active space self-consistent field method. The multireference configuration interaction method with the Davidson correction was used to obtain accurate energetics. Moreover, the conical intersections (CIs), which play a crucial role in photoisomerization, were also optimized. On the basis of the calculation results, the most favorable proposed reaction pathway is as follows: reactant→Franck-Condon region→TS(1) →CI→IM(0) →TS(0P) →product. The product was not directly formed through the CI, and the IM(0) existed on the S(0) state. These results show that the isomerization of 1,2-dihydro-1,2-azaborine involves both photoreactions and thermal reactions. The calculated results clarify recent experimental observations.
authors.affiliation: Department of Chemistry, The Catholic University of Korea, Bucheon, 420-743 (Republic of Korea). joonghankim@catholic.ac.kr.
authors.forename: Joonghan
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemistry, The Catholic University of Korea, Bucheon, 420-743 (Republic of Korea).
authors.forename: Jiwon
authors.initials: J
authors.lastname: Moon
authors.affiliation: Division of Metrology for Quality Life, Korea Research Institute of Standards and Science (KRISS), Daejeon (Republic of Korea). lim.jeongsik@kriss.re.kr.
authors.forename: Jeong Sik
authors.initials: JS
authors.lastname: Lim
keywords: conical intersections; multireference character; photoisomerization; reaction mechanisms; thermal reactions