title: Topological Aspects of the Skeletal Bonding in "Isocloso" Metallaboranes Containing "Anomalous" Numbers of Skeletal Electrons.
abstract: Removal of the transition metal vertex from an "isocloso" metallaborane having 9, 10, or 11 vertices and 2nu skeletal electrons leads to a B(n)()H(n)()(2)(-) ligand or isoelectronic derivative thereof having one open hexagonal face for hexahapto bonding to the transition metal and 2nu - 7 triangular faces. The numbers of available skeletal electrons and orbitals in such isocloso metallaboranes correspond to nu 2-electron 3-center bonds in nu of the 2nu - 4 faces of the original metallaborane deltahedron. This contrasts with the 2-electron nu-center core bond and the nu surface bonds in the closo metal-free B(n)()H(n)()(2)(-) and C(2)B(n)()(-)(2)H(n)() deltahedra with 2nu + 2 skeletal electrons. A diamond-square process removing an M-B edge from an isocloso metallaborane to give an "isonido" metallaborane converts a set of six skeletal orbitals from two 2-electron 3-center bonds into three 2-electron 2-center bonds.
authors.affiliation: Department of Chemistry, University of Georgia, Athens, Georgia 30602.
authors.forename: R. B.
authors.initials: RB
authors.lastname: King