Population Analysis of Titanocene Dicarboranyl by the Mulliken and NBO Methods: A Comparative Study

A broad systematic analysis of the orbital populations of a structurally complex d0 titanocene, having rare ligand-to-metal charge transfer excited states, was done in the Mulliken and NBO approximations using methods traditionally applied to simulate excited states and coordinative interactions. The Mulliken population analysis was shown to be highly sensitive to the basis set and failed to provide reliable characterization of the charge distribution in the target compound. The natural population analysis, an alternative to the Mulliken analysis, much better described atomic charges in target polar organometallics.