Allylmercuric iodide, reaction

In a subsequent paper10, details were given of experiments in which the concentration of added iodide was varied from 6 x 10 3 to 25 x 10" 3 M. The variation of the observed first-order rate coefficient (reactions were run with a large excess of iodide ion and hydrogen ion over the concentration of allylmercuric iodide) with [I - ] and [H+] was expressed by the equation... 

The volume of activation, A V, which is — RT 8 lnk)Jdp, has been suggested as a criterion of mechanism (Whalley, 1964). Known volumes of activation for A-SB2 reactions, measured near 25°, seem to be limited to olefin hydration (—12 cm3 mole-1 for isobutene at 35°, Baliga and Whalley, 1965) and allylmercuric iodide cleavage ( — 11 cm3 mole-1 at 25°, Halpem and Tinker, 1965). It is impossible to generalize from so few examples, but, in principle, it seems possible that AV is less dependent on structural ramification than AS, and therefore easier to interpret. Against this must be weighed the experimental difficulties in... 

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