title: Cobalt-dinitrogen complexes with weakened N-N bonds.
abstract: Reported N(2) complexes of cobalt do not have substantial weakening of the N-N bond. Using diketiminate ligands to enforce three-coordinate geometries, we have synthesized several novel CoNNCo complexes. In formally univalent complexes, cobalt is poorer than iron at weakening the N-N bond, but in formally zerovalent complexes, cobalt and iron give similar N-N weakening. The weakening is due to cobalt-to-N(2) pi-backbonding, and potassium cations pull more electron density into N(2). These results show that the low coordination number of a trigonal-planar geometry is impetus enough to make even the electronegative cobalt weaken the N-N bond of N(2).
authors.affiliation: Department of Chemistry, University of Rochester, Rochester, New York 14267, USA.
authors.forename: Keying
authors.initials: K
authors.lastname: Ding
authors.forename: Aaron W
authors.initials: AW
authors.lastname: Pierpont
authors.forename: William W
authors.initials: WW
authors.lastname: Brennessel
authors.forename: Gudrun
authors.initials: G
authors.lastname: Lukat-Rodgers
authors.forename: Kenton R
authors.initials: KR
authors.lastname: Rodgers
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Cundari
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Holland
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry
chemical_list: D028561:Transition Elements; D003035:Cobalt; D009584:Nitrogen