Against the Norm: Non Irving-Williams Transmetalation in Transition Metal Dimers.

We report the synthesis and characterization of three dinuclear 33' complexes, (), (), and ([CuMn(NO)]), that utilize the ligand, H (6,6'-dimethoxy-2,2'-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol). The relative stabilities of these complexes were investigated using experimental and computational techniques, revealing a non-Irving-Williams transmetalation, whereby a Mn ion can displace a Cu ion from its binding pocket in to yield the more stable complex. Magnetic characterization of the reported complexes revealed an unexpected ferromagnetic coupling between the two Cu ions of with = +63.0 cm.