Thermochemical Analysis of Intermolecular Vs. Intramolecular Reactions in Iridium Complexes

Transition metals are commonly used in catalytic reactions in academic and industrial settings. Transition metals have a variety of oxidation states and can bind ligands in a variety of geometries, including octahedral, tetrahedral, or square-planar coordination to name a few. The Cp*IrPPh₃ complex (1) was studied for its ability to activate C-H bonds under mild conditions. As observed in experimental work, complex 1 in benzene has the ability to undergo both intermolecular and intramolecular reactions in a nearly 1:1 ratio. Literature suggests that the intramolecular reaction should be favored. Computational methods were used to investigate the details of the intermolecular and intramolecular reaction mechanisms. With the detailed knowledge of the reaction mechanism, we can determine if the 1:1 ratio is a kinetic or thermodynamic effect.