Calorimetric Study of the Oxidative Addition of Acyl Chlorides to Iridium(I) Complexes in Solution, the Standard State, and the Gas Phase

Article abstract of DOI:10.1021/ja00409a025

Titration calorimetric methods have been used to determine enthalpy changes for the oxidative addition of acetyl chloride to trans- (L = PMe3, PMe2Ph, PMePh2, PPh2(p-Tol), PEt3, P(CH2Ph)3, P(t-Bu)Ph2, or P(OPh)3).These data were fitted to a two-parameter equation, -ΔH = A₀ + A₁θ + A₂ν.Heats of solution and sublimation were determined for and (CO)L2> (L = PMe3 or PEt3).Enthalpy changes for reaction in ethylene dichloride solution, the standard state, and the gas phase were evaluated for these compounds.The enthalpies of oxidative addition of RC(O)Cl (R = Me, Et, n-Pr, i-Pr, t-Bu, CH2Cl, CHCl2, or Ph) to trans- were determined.A value of D(Ir-C(O)CH3) = 205 +/- 46 kJ/mol has been obtained.