Publication Date:
2019
Description:
〈p〉The importance of conical intersections (CIs) in electronically nonadiabatic processes is well known, but their influence on adiabatic dynamics has been underestimated. Here, through combined experimental and theoretical studies, we show that CIs induce a barrier and regulate conversion from a precursor metastable intermediate (CI-R) to a deep well one. This results in bond-selective activation, influencing the adiabatic dynamics markedly in the C(〈sup〉1〈/sup〉D) + HD reaction. Theory is validated by experiment; quantum dynamics calculations on highly accurate ab initio potential energy surfaces yield rate coefficients and product branching ratios in excellent agreement with the experiment. Quasi-classical trajectory calculations reveal that the CI-R intermediate leads to unusual reaction mechanisms (designated as CH activation complex conversion and cyclic complex), which are responsible for large branching ratios. We also reveal that CI-R intermediates exist in other reactive systems, and the dynamical effects uncovered here may have general significance.〈/p〉
Electronic ISSN:
2375-2548
Topics:
Natural Sciences in General
Permalink