P-P Coupling and Terminal Metal-Phosphorus Intermediates.

Terminal metal-phosphorus (M-P) complexes are of significant contemporary interest as potential platforms for P-atom transfer (PAT) chemistry. Decarbonylation of metal-phosphaethynolate (M-PCO) complexes has emerged as a general synthetic approach to terminal M-P complexes. M-P complexes that are stabilized by strong M-P multiple bonds are kinetically persistent and isolable.

A Transient Iron Carbide Generated by Cyaphide Cleavage.

Despite their potential relevance as molecular models for industrial and biological catalysis, well-defined mononuclear iron carbide complexes are unknown, in part due to the limited number of appropriate C synthons. Here, we show the ability of the cyaphide anion (C≡P) to serve as a C source. The high spin ( = 2) cyaphide complex PhB(BuIm)Fe-C≡P (PhB(BuIm) = phenyl(tris(3--butylimidazol-2-ylidene)borate) is readily accessed using the new cyaphide transfer reagent [Mg(NacNac)(CP)] (NacNac = CH{C(CH)N(Dipp)} and Dipp = 2,6-di(iso-propyl)phenyl).

Hydrogen atom abstraction by a high spin [Fe=S] complex.

Iron sulfur clusters are critical to a plethora of biological processes; however, little is known about the elementary unit of these clusters, namely the [Fe=S] fragment. Here, we report the synthesis and characterization of a terminal iron sulfido complex. Despite its high spin ( = 5/2) ground state, structural, spectroscopic, and computational characterization provide evidence for iron sulfur multiple bond character.