Kinetics of deuterium isotope exchange between 2-methylpropane-2-thiol and propane-2-thiol in aprotic solvents
Abstract
The rate constants for bimolecular deuterium isotope exchange between 2-methylpropane-2-thiol and propane-2-thiol in C6D12, CCl4, (CD3)2CO, HCON(CH3)2, (CD2)4O, and (CH3)2SO solutions were determined by use of 1H n.m.r. analysis. The rate constants, k, and activation enthalpy, ΔH‡, decrease, and entropy, –ΔS‡, increases, with an increase in the ability of the solvents to form hydrogen bonds with alkanethiols. The rate constant of concerted hydrogen transfer inside the cyclic dimer of alkanethiols with two H-bonds, k3, increases with increasing dielectric constant of the solvent.