title: New reactions of terminal hydrides on a diiron dithiolate.
abstract: Mechanisms for biological and bioinspired dihydrogen activation and production often invoke the intermediacy of diiron dithiolato dihydrides. The first example of such a Fe2(SR)2H2 species is provided by the complex [(term-H)(μ-H)Fe2(pdt)(CO)(dppv)2] ([H1H](0)). Spectroscopic and computational studies indicate that [H1H](0) contains both a bridging hydride and a terminal hydride, which, notably, occupies a basal site. The synthesis begins with [(μ-H)Fe2(pdt)(CO)2(dppv)2](+) ([H1(CO)](+)), which undergoes substitution to afford [(μ-H)Fe2(pdt)(CO)(NCMe)(dppv)2](+) ([H1(NCMe)](+)). Upon treatment of [H1(NCMe)](+) with borohydride salts, the MeCN ligand is displaced to afford [H1H](0). DNMR (EXSY, SST) experiments on this complex show that the terminal and bridging hydride ligands interchange intramolecularly at a rate of 1 s(-1) at -40 °C. The compound reacts with D2 to afford [D1D](0), but not mixed isotopomers such as [H1D](0). The dihydride undergoes oxidation with Fc(+) under CO to give [1(CO)](+) and H2. Protonation in MeCN solution gives [H1(NCMe)](+) and H2. Carbonylation converts [H1H](0) into [1(CO)](0).
authors.affiliation: School of Chemical Sciences University of Illinois - Urbana , Urbana, Illinois 61801, United States.
authors.forename: Wenguang
authors.initials: W
authors.lastname: Wang
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Rauchfuss
authors.forename: Lingyang
authors.initials: L
authors.lastname: Zhu
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zampella
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D013438:Sulfhydryl Compounds; C002007:dithiol-iron(III)-sulfide complex; D006859:Hydrogen