An experimental and computational study of sulfur-modified nucleophilicity in a dianionic NiN2S2 complex. uri icon

abstract

  • The dianionic NiN2S2 complex, Ni(ema)2-, ema=N,N'-ethylenebis-2-mercaptoacetamide, known as a reasonable model of the tripeptide complex Ni(CGC)2- (C=cysteine; G=glycine) with respect to the two carboxyamido nitrogens and cis-dithiolates in a (N2S2)4- ligand scaffold as found in acetyl CoA synthase, has been explored for S-based reactivity toward oxygenation and alkylation. The isolation and structural characterization of a sulfinato species, [Et4N]2[Ni(ema).O2], prepared through a unique direct reaction of molecular O2 with crystalline [Et4N]2[Ni(ema)] is described. Reaction of [Et4N]2[Ni(ema)] with Br(CH2)3Br yields a neutral N2S2 macrocyclic complex shown by DFT computations and electrostatic-potential mapping to be opposite in electron distribution from the neutral NiN2S2 complexes in which the anionic charge is localized on sulfur.

published proceedings

  • Inorg Chem

author list (cited authors)

  • Green, K. N., Brothers, S. M., Jenkins, R. M., Carson, C. E., Grapperhaus, C. A., & Darensbourg, M. Y.

citation count

  • 29

complete list of authors

  • Green, Kayla N||Brothers, Scott M||Jenkins, Roxanne M||Carson, Cody E||Grapperhaus, Craig A||Darensbourg, Marcetta Y

publication date

  • September 2007