A ³⁵Cl magnetic resonance study of chloride exchange on indium(III) and thallium(III) in aqueous hydrochloric acid solution

Abstract

The parameters describing chloride exchange on indium(III), determined by ³⁵Cl N.M.R., are: k(298 K)= (8.8±0+4) x 10⁶ s^-1, ΔH^? = 45.7±2.3 kJ mol^-1 and ΔS^? = 42±8 J mol^-1 K^-1; and k(298 K)= (2.0±0.1)x10⁶ s^-1, ΔH^? = 37.7±1.9 kJ mol^-1, and ΔS^? = 3±6 J mol^-1 K^-1 in 10.95M and 7.00M aqueous hydrochloric acid respectively, calculated from the observed exchange rate k_ex4[InCl₄(H2O)2^-].    For thallium(III) lower limits of k_ex(219 K) = 1.6 x 10⁶ s^-1 and 1.3 x 106 s^-1 were obtained in 10.95M and 7.00M aqueous hydrochloric acid, respectively, where [TlCl₆]^3- is assumed to be the exchanging species.