title: A theoretical analysis of supported quintuple and quadruple chromium-chromium bonds.
abstract: The extended transition state (ETS) energy decomposition scheme has been combined with the natural orbitals for chemical valence (NOCV) density decomposition method (ETS-NOCV) in a study on the shortest, fully supported metal-metal bond (Cr-Cr = 1.73 Å) in Cr2[Ar'NC(NMe2)NAr']2 [Ar' = C6H3-2,6(C6H3-2,6-Pr(i)2)2]. The scope of the ETS-NOCV method is further demonstrated by a metal-metal bond analysis of the paddlewheel M2(O2CCH3)4 (M = Cr, Mo, W) complexes. The influence of axial ligands as well as R' goups on the bridging ligands is also analyzed. In addition to the quintuple bonding components (σ(2), π(4), δ(4)) for Cr2[Ar'NC(NMe2)NAr']2 and quadruple components (σ(2), π(4), δ(2)) for the paddlewheel complexes, we notice additional stability (17-27 kcal/mol) introduced to the metal-metal bond from participation of the lone pairs residing on the π-systems of the bridging X-C-X (X = N, O) ligand. This is to our knowledge the first time that the strength of the metal-metal bonding components has been determined in a supported metal-metal bond by an energy decomposition scheme.
authors.affiliation: Department of Chemistry, University of Calgary, Calgary, Alberta Canada, T2N1N4.
authors.forename: Sylvester
authors.initials: S
authors.lastname: Ndambuki
authors.forename: Tom
authors.initials: T
authors.lastname: Ziegler