Do the Structural Changes Defined by the Electron Density Topology Necessarily Affect the Picture of the Bonding?

The analysis of domain averaged Fermi holes (DAFH) was applied to the elucidation of the nature of the bonding interactions in supported metal carbonyls, where multicenter bonding of the bridging ligands and direct metal-metal bonds are considered as possible alternatives. The main focus is directed on the detailed scrutiny of the possible impact of the changes in the topology of electron density induced by the systematic variation of the geometry of the studied carbonyls on the picture of the bonding provided by the visual description in terms of DAFH analysis. It has been shown that irrespective of the dramatic changes in the topology of electron density exemplified by the existence and/or the lack of direct metal-metal bond path, the DAFH picture of the bonding remains practically unaffected and in all cases consistently suggests that the bonding of the bridging ligands exhibits the typical features of delocalized 3c-2e bonding.