MAGNETIC-INTERACTIONS IN A 3-CENTER, 4-ELECTRON SYSTEM

The results of ab initio electronic structure calculations on model four electron, three center systems are used to develop a general understanding of the effect of bridging ligands on metal-metal magnetic interactions. An expression is obtained for the energy difference between singlet and triplet states as a function of the overlap with the bridging ligand. A linear relation is derived and computationally verified between the singlet-triplet splitting and the fourth power of the overlap between the symmetric combination of magnetic orbitals and the bridge orbitals.