Proton-Coupled Reduction of an Iron Cyanide Complex to Methane and Ammonia.
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.
Division of Chemistry and Chemical Engineering, California Institute of Technology, USA.
Jonathan
J
Rittle
Division of Chemistry and Chemical Engineering, California Institute of Technology, USA. jpeters@caltech.edu.
Jonas C
0000-0002-6610-4414
JC
Peters
D000641:Ammonia / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003486:Cyanides / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008697:Methane / Q000737:chemistry*; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D011522:Protons
D056831:Coordination Complexes; D003486:Cyanides; D008024:Ligands; D011522:Protons; D000641:Ammonia; D007501:Iron; D008697:Methane
carbyne ligands; cyanide cleavage; iron complexes; nitrogen fixation; nitrogenase