title: Sandwich compounds of transition metals with cyclopolyenes and isolobal boron analogues.
abstract: A series of sandwich compounds of transition metals (M=Ni, Fe, Cr) with cyclic hydrocarbon (M(CH)(n)) and borane (M(BH(2))(n)), ligands (including mixed hydrocarbon/borane sandwiches) has been studied using density functional theory (B3LYP/6-311+G(df,p)). Multicenter bonding between the central metal atom and basal cycloborane rings provides stabilization to planar cycloborane species. Large negative NICS values allude to aromatic character in the cycloboranes similar to the analogous cyclic hydrocarbons. The ability of cycloborane sandwiches to stabilize attached carbocations, radicals and carbanions is also assessed.
authors.affiliation: Institute of Physical and Organic Chemistry, Southern Federal University, Southern Research Center of Russian Academy of Sciences, Rostov-on-Don, Russian Federation.
authors.forename: Tatyana N
authors.initials: TN
authors.lastname: Gribanova
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Starikov
authors.forename: Ruslan M
authors.initials: RM
authors.lastname: Minyaev
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Minkin
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Siebert
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Tantillo