Computational Modeling of Complexes of Penta-Ammine Osmium (II) with Aromatic Ligands

Abstract Complexation of aromatic species with penta-ammine osmlium (II)[Os]has remarkable effects on their structure and reactivity. The η2-complexed dearomatized ligand can be encouraged to react in ways of great convenience in synthetic projects. We model the structure of complexes of [Os] with various descriptions of correlation and in various bases. The most satisfactory method for structures is a perturbation correlation corrected model (MP2) with a hybrid basis, 6-31G* on all but osmium, and the LANL2DZ basis and associated pseudopotential for that heavy atom. A B3LYP/hybrid scheme seems to produce better estimates of binding and isomerization energies for a range of ligands, including hydrocarbons, heteroaromatics, and substituted benzenes. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003