Reactive mode composition factor analysis of transition states: the case of coupled electron–proton transfers

Abstract

The kinetic energy distribution in the reactive mode in transition states correlates the asynchronicity of CPET with relative kinetic isotope effects.

Statistical analysis of C–H activation by oxo complexes supports diverse thermodynamic control over reactivity

“…For instance, parameters such as Δ G PCET and | η | have been shown to correlate with tunneling. 23,57 …”

Kinetic Isotope Effects and Hydrogen Tunnelling in PCET Oxidations of Ascorbate: New Insights into Aqueous Chemistry?

“…Contributions from excited states could lead to either a decrease or an increase of the KIE with temperature, as observed experimentally in the case of ubiquinol analog oxidation [74]. Recently, reactive mode composition factor method has been applied to predict KIE and hydrogen tunnelling in a series of PCET reactions [56].…”

“…Kinetic isotope effect, the change of rate that occurs upon isotopic substitution, is a widely used tool for elucidating a reaction mechanism, particularly in the study of the hydrogen (H + , H − , H•) transfer reactions and the role of hydrogen tunnelling (see -6,55]. Therefore, the analysis of KIE reveals also the fundamental features of PCET reactions [4,6,[9][10][11][12][13][14]47,[56][57][58][59]. KIE can be used to distinguish between concerted and stepwise PCET reactions.…”

“…Recently, reactive mode composition factor method has been applied to predict KIE and hydrogen tunnelling in a series of PCET reactions [56].…”

Bifurcating reactions: distribution of products from energy distribution in a shared reactive mode

“…Specifically, the presented method relies on the kinetic energy distribution within the reactive mode at TS 1 , as introduced by us and already applied to coupled electron-proton transfer (CEPT) reactivity and post-CEPT selectivity. 26,27 Here, we first concisely summarize the principles of the method (denoted as Reactive Mode Composition Factor -RMCF) and later assess its accuracy in the quantification of product ratios of bifurcating organic reactions and compare its performance with existing protocols. We also briefly discuss the chemical insight provided by the analysis and the limitations of the method.…”