Reactions of trifluoromethyl radicals with iodine and hydrogen iodide

Abstract

The reactions CF₃+I₂→CF₃I+I (2) CF₃+HI→ CF₃H+I (3) have been studied by competitive methods. Use of our previous Arrhenius parameters for reaction (2) leads to, k₃= 5.4 × 10¹¹ exp –500/RT, cm³ mole^–1 sec^–1. Arrhenius parameters are summarized for the reactions CF₃+X₂→CF₃X+X and CF₃+HX→CF₃H+X, where X = Cl, Br or I and also for CF₃+H₂→CF₃H+H and CF₃+H₂S→CF₃H+SH. These Arrhenius parameters are combined with thermodynamic data to give Cl+CF₃Cl→Cl₂+CF₃, k= 1.9 × 10¹⁴ exp –31,300/RT, cm³ mole^–1 sec^–1. Br+CF₃Br→Br₂+CF₃, k= 6.5 × 10¹³ exp –24,300/RT, cm³ mole^–1 sec^–1. I+CF₃I→I₂+CF₃, k= 7.4 × 10¹³ exp –17,800/RT, cm³ mole^–1 sec^–1. H+CF₃H→H₂+CF₃, k= 3.2 × 10¹² exp –11,200/RT, cm³ mole^–1 sec^–1. SH+CF₃H→H₂S+CF₃, k= 1.1 × 10¹² exp –19,100/RT, cm³ mole^–1 sec^–1.