Cobalt-dinitrogen complexes with weakened N-N bonds.
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).
Ding
Keying
K
Department of Chemistry, University of Rochester, Rochester, New York 14267, USA.
Pierpont
Aaron W
AW
Brennessel
William W
WW
Lukat-Rodgers
Gudrun
G
Rodgers
Kenton R
KR
Cundari
Thomas R
TR
Bill
Eckhard
E
Holland
Patrick L
PL
D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry
D028561:Transition Elements; D003035:Cobalt; D009584:Nitrogen