Electrochemical reduction of tert-butyl chloride-Computational study

In this work kinetics of the electrochemical reduction of the tert-butyl chloride molecule are studied. The two-dimensional potential surface E(x, y) was obtained from the Hamiltonian model used earlier to study quantum effects on the reaction rate of the same reaction. In series of molecular dynamics simulations two different models, isotropic (γx = γy) and anisotropic (γx > γy), of the friction parameters for the solvent (γx) and for the C-Cl bond (γy) were considered. An influence of several factors, such as an overpotential, a solvent friction coefficient and a temperature, on the rate constants k obtained with the two models are presented and compared to the results obtained for the non-adiabatic mechanism. It is shown, that the anisotropic model predicts generally much smaller rates when compared to those calculated with the isotropic model and also with the non-adiabatic model. On the curves k(γx) the turnover region is very well defined for relatively low frictions in the isotropic case, while for the anisotropic case it is shifted towards much higher γx values. In all simulations the saddle point avoidance phenomenon was observed and its extent for different models and reaction conditions is discussed. Transfer coefficients α obtained for adiabatic and non-adiabatic reaction mechanisms as a function of the overpotential and temperature are also presented.