Evidence for the Incursion of Intermediates in the Hydrolysis of Tertiary, Secondary, and Primaty Substrates

Article abstract of DOI:10.1021/ja00528a011

The temperature dependence related to a series of solvolytic displacement reactions of primary, secondary, and tertiary carbon centers are examined using a new equation.The equation is derived by integrating the van't Hoff isochore in a form related to the absolute rate theory on the assumption that the heat capacity of activation (ΔG_p<*>) is constant.Unexpectedly, the new equation is capable of correctly sensing changes in ΔC_p<*> with temperature.The new equation is used to show that in some instances ΔC_p<*> is partly abnormal and derives from the nonunitary nature of the displacement in a way outlined previously by Albery and Robinson.The significance of this new mechanistic tool is considered in relation to the displacement reaction of 2-bromopropane in heavy water and the reactions of adamantyl nitrate, tert-butyl chloride, S-propyl methanesulphonate, m-trifluoromethylbenzyl nitrate, and ethyl bromide with ordinary water.