Fm. Elzawawy et al., KINETICS OF CHLORINE ISOTOPE EXCHANGE-REACTION BETWEEN SODIUM CHLORIDE-36 AND TRIPHENYLTIN CHLORIDE IN MIXED-SOLVENTS, Journal of radioanalytical and nuclear chemistry, 164(3), 1992, pp. 141-151
Isotope exchange reaction between NaCl-36 and triphenyltin chloride in
dioxane-water (80:20% w/w) and ethanol-water (90:10% w/w) mixed solve
nts has been studied at 25, 35 and 50-degrees-C. The exchange reaction
was found to proceed via a bimolecular S(N)2, limiting mechanism with
reaction rates depending on the solvent used. Inhibition of the excha
nge in ethanol-water is probably due to solvation of chloride ion thro
ugh hydrogen bond formation. The rate laws for the exchange reactions
are: R(e) = 3.24 x 10(9) e-65550/RT [Ph3SnCl] alpha [NaCl] in dioxane-
water and R(e) = 6.61 x 10(8) e-69600/RT [Ph3SnCl] alpha [NaCl] in eth
anol-water, where alpha is the degree of dissociation of NaCl and R(e)
is the rate of exchange in mol l-1 s-1. The activation parameters DEL
TA-H, DELTA-S* and DELTA-G* are reported.