A density functional theory study of the oxidative addition of methyl iodide to square planar [Rh(acac)(P(OPh)3)2] complex and simplified model systems

The transition state for the oxidative addition reaction [Rh(acac)(P(OPh)3)2] + CH3I, as well as two simplified models viz. [Rh(acac)(P(OCH3)3)2] and [Rh(acac)(P(OH)3)2], are calculated with the density functional theory (DFT) at the PW91/TZP level of theory. The full experimental model, as well as the simplified model systems, gives a good account of the experimental Rh-ligand bond lengths of both the rhodium(I) and rhodium(III) β-diketonatobis(triphenylphosphite) complexes. The relative stability of the four possible rhodium(III) reaction products is the same for all the models, with trans-[Rh(acac)(P(OPh)3)2(CH3)(I)] (in agreement with experimental data) as the most stable reaction product. The best agreement between the theoretical and experimental activation parameters was obtained for the full experimental system.