Noncovalent metal-metal interactions: the crucial role of london dispersion in a bimetallic indenyl system.

The nature of the "heterodox" metal-metal bond in bimetallic indenyl systems is revealed by a new high-level electronic structure analysis procedure based on perturbation theory within a localized molecular orbital basis. Surprisingly strong metal-metal interactions are found, and their origin in London dispersion effects has been uncovered. The importance of intramolecular van der Waals interactions, even for quite small organometallic systems, is highlighted.