H/D Exchange Reactions in Dinuclear Iron Thiolates as Activity Assay Models of Fe−H₂ase

Muonium Chemistry at Diiron Subsite Analogues of [FeFe]‐Hydrogenase

“…4.5 kG signals has been probed by computational simulation of plausible structures, from which Δ 0 values have been calculated 22. For the known solid‐state structure of 2 which has a basal–basal deployment of phosphine ligands,16 the high‐field signal at 8.5 kG is consistent with the Mu being bound to iron either in a bridging or terminal position (Figure 4). For 3 , only the bridging muonide fits with the experimental value.…”

“…In this work, we have examined three [FeFe]‐hydrogenase subsite models, each of which illustrate a different aspect of hydride chemistry (Figure 1). Thus, complex 1 is known to engage in electrocatalysis, in which an electron and a proton are added successively;15 complex 2 protonates at the metal–metal bond16 enabling subsequent electronation to yield a mixed‐valence Fe(1.5)Fe(1.5) hydride (cf. H‐atom addition);17 whilst complex 3 possesses the bis‐cyanide coordination found in the enzyme and has been shown to reconstitute an apoenzyme 18, 19, 20…”

Molecular Biology of Microbial Hydrogenases

“…Synthetic chemical compounds capable of mimicking the [NiFe] active site (e.g. Alvarez et al, 2001;Sellman et al, 2002) and the di-iron subsite of the H-cluster of [FeFe]-H 2 ases (Zhao et al, 2001(Zhao et al, , 2002George et al, 2002;Gloaguen et al, 2001Gloaguen et al, , 2002Kayal and Rauchfuss, 2003;Ott et al, 2003;Nehring and Heinekey, 2003;Salyi et al, 2003) have been assembled. The chemistry of these synthetic [NiFe] and [FeFe] systems and their pertinence as new electrocatalytic systems for hydrogen production or uptake is described and discussed in the review by Evans and Pickett (2003).…”

[FeFe] Hydrogenase: Protonation of {2Fe3S} Systems and Formation of Super‐reduced Hydride States

“…These roles include nitrogen fixation, [1] hydrogen evolution/uptake by the [FeFe] and [NiFe] hydrogenases, [2] heterolytic cleavage of molecular hydrogen at [Fe] hydrogenase, [3,4] and such hydrides are likely involved in enzymic catalysis of the interconversion of CO 2 and CO. [5] They have an implicit role as intermediates in electrocatalytic bioinorganic systems which model natural processes. [6] Synthetic bridging hydride species at {2Fe2S} cores are structurally well-established [7][8][9] and the chemistry of terminal hydrides at such centers is rapidly developing. [10][11][12][13] Related {2Fe3S} cores have a somewhat closer structural homology to the ironsulfur core of the [FeFe]-hydrogenase subsite.…”