Development of Five-Coordinate Zinc Mono- and Dithiolates as S-Donor Metalloligands: Formation of a Zn−W Coordination Polymer

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• 作者：Elky Almaraz ; William S. Foley ; Jason A. Denny ; Joseph H. Reibenspies ; Melissa L. Golden ; Marcetta Y. Darensbourg
• 刊名：Inorganic Chemistry
• 出版年：2009
• 出版时间：June 15, 2009
• 年：2009
• 卷：48
• 期：12
• 页码：5288-5295
• 全文大小：857K
• 年卷期：v.48,no.12(June 15, 2009)
• ISSN：1520-510X

文摘

The synthesis and isolation of mono- and dithiolate-bridged Zn(μ-SR)_nW(CO)_m (where n = 1, m = 5; n = 2, m = 4) species from the dimeric N,N′-bis(2-mercaptoethyl)-1,4-diazacycloheptanezinc(II), [Zn-1′]₂, and the monomeric [N-(3-thiabutyl)-N′-(3-thiapentaneoate)-1,5-diazacycloheptane]zinc(II), Zn-1′-Ac, are described. Upon cleavage of the dimeric [Zn-1′]₂ with Na⁺[ICH₂CO₂]⁻, the resulting Zn-1′-Ac product is isolated as a monomeric, five-coordinate Zn(N₂SS′O) complex equipped with one available Zn-bound thiolate for further reactivity. Cleavage of [Zn-1′]₂ with [Et₄N]⁺Cl⁻ afforded a monomeric intermediate, [Zn-1′-Cl]⁻, containing two Zn-bound thiolates. The zinc mono- and dithiolato complexes demonstrated reactivity toward labile-ligand tungsten carbonyl species, (THF)W(CO)₅ and (pip)₂W(CO)₄, to yield respectively [(Zn-1′-Ac)W(CO)₅]_x and [(Zn-1′-Cl)W(CO)₄]⁻ complexes that were isolated and characterized spectroscopically and via X-ray diffraction. Upon binding to W(CO)₅, the five-coordinate Zn(N₂SS′O) complex becomes six-coordinate within the coordination polymer [(Zn-1′-Ac)W(CO)₅]_x, in which the acetate tether of each molecule provides an O donor to occupy the octahedral axial position of a neighboring moiety. The [(Zn-1′-Cl)W(CO)₄]⁻ dithiolate-bridged complex maintains a five-coordinate, square-pyramidal [Zn(N₂S₂Cl)]⁻ center, utilizing a chloride as the apical donor and resulting in an overall anionic complex. The addition of CO(g) to the [(Zn-1′-Cl)W(CO)₄]⁻ complex was monitored by IR spectroscopy, which showed the emergence of [(Zn-1′-Cl)W(CO)₅]⁻.