title: Monoanionic bis(carbene) pincer complexes featuring cobalt(I-III) oxidation states.
abstract: The synthesis and characterization of a series of cobalt complexes featuring a pincer bis(carbene) ligand of the meta-phenylene-bridged bis-N-heterocyclic carbene ((Ar)CCC, Ar = 2,6-diispropylphenyl or mesityl) are reported. Cleavage of the aryl C-H bond of the ligand was achieved in a one-pot metalation procedure using Co(N(SiMe3)2)2(py)2, an equivalent of exogenous base, and trityl chloride to form the ((DIPP)CCC)CoCl2py complex. This species could be reduced to the Co(ii) and Co(i)-N2 molecules with the appropriate equivalents of reductant. Subsequent generation of ((Mes)CCC)Co(I-III) derivatives with the mesityl ligand proceeded in good yields. A suite of characterization techniques and the interconversion between all three oxidation states of the cobalt complexes is described.
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Abdulrahman D
authors.initials: AD
authors.lastname: Ibrahim
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Kenan
authors.initials: K
authors.lastname: Tokmic
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Marshall R
authors.initials: MR
authors.lastname: Brennan
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Dongyoung
authors.initials: D
authors.lastname: Kim
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Matson
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nilges
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Jeffery A
authors.initials: JA
authors.lastname: Bertke
authors.affiliation: School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA. fout@illinois.edu.
authors.forename: Alison R
authors.initials: AR
authors.lastname: Fout