A kinetic and mechanistic study of the reaction between bis-p-ethoxyphenyl ditelluride and molecular iodine in solution

Abstract

The title reaction in toluene has been examined spectrophotometrically. The data are consistent with equations (1)–(3)(R =p-EtOC₆H₄). The rate constants k₁ and k₃ are 56 ± 2 dm³ mol^–1 s^–1 at R₂Te₂+ [graphic omitted] 2RTel (1) RTel + I₂ [graphic omitted] RTe(I₃)(2) RTe(I₃) [graphic omitted] RTel(I)₃(3) 7 °C and 6.2 × 10^–4 s^–1 at 25 °C, respectively. The equilibrium constant K₂ is 1 570 dm³ mol^–1 at 25 °C, and ΔH₂=–22 ± 4 kJ mol^–1. The activation parameters for the final step are ΔH^‡= 44 ± 5 kJ mol^–1 and ΔS^‡=–160 ± 15 J K^–1 mol^–1.