title: Electronically unsaturated three-coordinate chloride and methyl complexes of iron, cobalt, and nickel.
abstract: Three-coordinate organometallic complexes are rare, especially with the prototypical methyl ligand. Using a hindered, rigid bidentate ligand (L), it is possible to create 12-electron methyliron(II) and 13-electron methylcobalt(II) complexes. These complexes are thermally stable, and (1)H NMR spectra suggest that the low coordination number is maintained in solution. Attempts to create the 14-electron LNiCH(3) led instead to the three-coordinate nickel(I) complex LNi(THF). Single crystals of LMCH(3) are isomorphous with the new three-coordinate chloride complexes LNiCl and LCoCl. Along with the recently reported LFeCl (Smith, J. M.; Lachicotte, R. J.; Holland, P. L. Chem. Commun. 2001, 1542), these are the only examples of three-coordinate iron(II), cobalt(II), and nickel(II) complexes with terminal chloride ligands, enabling the systematic evaluation of the effect of coordination number and metal identity on M-Cl bond lengths. Electronic structure calculations predict the ground states of the trigonal complexes.
authors.affiliation: Department of Chemistry, University of Rochester, Rochester, New York 14627, USA. holland@chem.rochester.edu
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Holland
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Cundari
authors.forename: Lanyn L
authors.initials: LL
authors.lastname: Perez
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Eckert
authors.forename: Rene J
authors.initials: RJ
authors.lastname: Lachicotte