Metal-metal bonding in 1st, 2nd and 3rd row transition metal complexes: a topological analysis.

A topological analysis based on density functional electronic and spin densities of the bonding characteristics in a series of Fe, Ru, Os, Tc and Rh dimers and trimers bridged, respectively, by μ-1,8-naphthyridine (nap) and μ-2,2'-dipyridylamine (dpa) is presented. By this simple qualitative analysis, we were able to determine the electronic ground state and correlated bonding order for a number of complexes potentially involved in extended metal atom chains (EMAC). Furthermore, we showed in the Ru dimer that it was possible to control the spin state simply by changing the bonded counter-anion. Graphical Abstract Electron localization analysis of the bonding properties in [M2(nap)4Cl2]2+ and [M3(dpa)4(Cl2] complexes.