Division of Chemistry and Chemical Engineering, California Institute of Technology, USA.
Angew Chem Int Ed Engl. 2016 Sep 26;55(40):12262-5. doi: 10.1002/anie.201606366. Epub 2016 Sep 8.
Nitrogenase enzymes mediate the six-electron reductive cleavage of cyanide to CH4 and NH3 . Herein we demonstrate for the first time the liberation of CH4 and NH3 from a well-defined iron cyanide coordination complex, [SiP(iPr) 3 ]Fe(CN) (where [SiP(iPr) 3 ] represents a tris(phosphine)silyl ligand), on exposure to proton and electron equivalents. [SiP(iPr) 3 ]Fe(CN) additionally serves as a useful entry point to rare examples of terminally-bound Fe(CNH) and Fe(CNH2 ) species that, in accord with preliminary mechanistic studies, are plausible intermediates of the cyanide reductive protonation to generate CH4 and NH3 . Comparative studies with a related [SiP(iPr) 3 ]Fe(CNMe2 ) complex suggests the possibility of multiple, competing mechanisms for cyanide activation and reduction.
固氮酶介导氰化物的六电子还原裂解生成甲烷和氨。本文首次证明了在质子和电子等价物的作用下,从结构明确的铁氰化物配位配合物[SiP(iPr) 3 ]Fe(CN)(其中[SiP(iPr) 3 ]代表三(膦)硅基配体)中释放出甲烷和氨。[SiP(iPr) 3 ]Fe(CN)还可作为端基 Fe(CNH)和 Fe(CNH2 )物种的有用入口,这些物种与初步的机理研究一致,是氰化物还原质子化生成甲烷和氨的合理中间体。与相关的[SiP(iPr) 3 ]Fe(CNMe2 )配合物的比较研究表明,氰化物的活化和还原可能存在多种竞争机制。