Predictions of Geometries and Multiplicities of the Manganese−Oxo Intermediates in the Jacobsen Epoxidation

[formula: see text] The geometries and multiplicities of models of the manganese(III)-salen catalyst and the manganese(V)-oxo Intermediate in the Jacobsen epoxidation were explored with density functional theory (Becke3LYP). Mn(III) complexes are quintet ground states, while ligands influence whether quintet, triplet, or singlet states are lowest in energy for Mn(V)-oxo complexes. Geometries and multiplicities and their implications for stereoselectivity are described.