An Experimental and Computational Study of Sulfur-Modified Nucleophilicity in a Dianionic NiN2S2 Complex
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- 作者：Kayla N. Green ; Scott M. Brothers ; Roxanne M. Jenkins ; Cody E. Carson ; Craig A. Grapperhaus ; Marcetta Y. Darensbourg
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：September 3, 2007
- 年：2007
- 卷：46
- 期：18
- 页码：7536 - 7544
- 全文大小：348K
- 年卷期：v.46,no.18(September 3, 2007)
- ISSN：1520-510X
文摘
The dianionic NiN2S2 complex, Ni(ema)2-, ema = N,N'-ethylenebis-2-mercaptoacetamide, known as a reasonablemodel of the tripeptide complex Ni(CGC)2- (C = cysteine; G = glycine) with respect to the two carboxyamidonitrogens and cis-dithiolates in a (N2S2)4- ligand scaffold as found in acetyl CoA synthase, has been explored forS-based reactivity toward oxygenation and alkylation. The isolation and structural characterization of a sulfinatospecies, [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 shownby DFT computations and electrostatic-potential mapping to be opposite in electron distribution from the neutralNiN2S2 complexes in which the anionic charge is localized on sulfur.