Evidence for the Formation of Terminal Hydrides by Protonation of an Asymmetric Iron Hydrogenase Active Site Mimic
Abstract
Treatment of [Fe2(μ-pdt)(CO)6] [pdt = S(CH2)3S] with dppe (Ph2PCH2CH2PPh2) in refluxing toluene affords the asymmetric complex [Fe2(μ-pdt)(CO)4(dppe)] (1). Protonation of 1 with HBF4−Et2O in CH2Cl2 gives at room temperature the μ-hydrido derivative [Fe2(μ-pdt)(CO)4(dppe)(μ-H)](BF4) (2). Monitoring the reaction by 1H, 31P, and 13C NMR at low temperature reveals unambiguously that the process of the protonation of 1 implies terminal hydride intermediates.