405883-64-9Relevant academic research and scientific papers
Oxidative addition of phosphine-tethered thiols to iron carbonyl: Binuclear phosphinothiolate complexes, (μ -SCH2CH2PPh2)2Fe2 (CO)4, and hydride derivatives
Zhao, Xuan,Hsiao, Yui-May,Lai, Chia-Huei,Reibenspies, Joseph H.,Darensbourg, Marcetta Y.
, p. 699 - 708 (2002)
The mononuclear complex Fe(CO)4(PPh2CH2CH2SH), 1, is isolated as an intermediate in the overall reaction of PPh2CH2CH2SH with [Fe0(CO)4] sources to produce binuclear bridging thiolate complexes. Photolysis is required for loss of CO and subsequent S-H activation to generate the metal-metal bonded FeI-FeI complex, (μ -SCH2-CH2PPh2)2Fe2 (CO)4, 2. Isomeric forms of 2 derive from the apical or basal position of the P-donor ligand in the pseudo square pyramidal S2Fe(CO)2P coordination spheres. This position in turn is dictated by the stereochemistry of the μ-S-CH2 bond, designated as syn or anti with respect to the Fe2S2 butterfly core. Addition of strong acids engages the FeI-FeI bond density as a bridging hydride, [(μ-H)-anti-2]+[SO3CF3]- or [(μ-H)-syn-2]+[SO3CF3]-, with formal oxidation to FeII-H-FeII. Molecular structures of anti-2, syn-2, and [(μ-H)-anti-2]+[SO3CF3]- were determined by X-ray crystallography and show insignificant differences in distance and angle metric parameters, including the Fe-Fe bond distances which average 2.6 A. The lack of coordination sphere rearrangements is consistent with the ease with which deprotonation occurs, even with the weak base, chloride. The FeI-FeI bond, supported by bridging thiolates, therefore presents a site where a proton might be taken up and stored as a hydride without impacting the overall structure of the binuclear complex.
