Coordination chemistry of dihydrogen

Heinekey, D. Michael; Oldham, Warren J.

doi:10.1021/cr00019a004

Cited by 598 publications

(413 citation statements)

References 40 publications

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“…Since 1984 it has become clear that, as discovered by Kubas et al [118], in a number of model compounds of transition metals molecular hydrogen can act as a ligand [50,98,119] in a side-on configuration [164]. This led Crabtree [50] to propose that dihydrogen might well be a ligand to Ni(III) in hydrogenases.…”

Section: Nia(1)mentioning

confidence: 99%

Nickel hydrogenases: in search of the active site

Albracht

1994

Biochimica et Biophysica Acta (BBA) - Bioenergetics

467

478

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Section: Nia(1)mentioning

confidence: 99%

Nickel hydrogenases: in search of the active site

Albracht

1994

Biochimica et Biophysica Acta (BBA) - Bioenergetics

467

478

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“…The other well established instances of such increased hydrogen coordination numbers arising in molecular chemistry are those of (i) metal complexes with bridging hydride ligands (Teller & Bau, 1981), (ii) so-called a-bond complexes (Brookhart, Green & Wong, 1988;Crabtree, 1993) in which three-centre two-electron X--H.-.M bonds are formed (X = B, C, Si, P, S, Ge, Sn; M = transition metal), and (iii) complexes with molecular hydrogen ligands, 712-H2 (Kubas, 1988;Crabtree, 1990;Jessop & Morris, 1992;Heinekey, 1993), which can be considered as a special class of a-bond complexes.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen bonds involving transition metal centres – a brief review

Brammer¹,

Zhao²,

Ladipo³

et al. 1995

Acta Crystallogr Sect B

142

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Hydrogen bonding is a topic which has received much attention over the years and continues to do so as the importance of such interactions is established in all areas of chemistry. The class of hydrogen bonds that directly involves electron-rich transition metal centres in the three-centre interaction has received little attention until quite recently. Such interactions are of importance in understanding intermolecular interactions between organometallic molecules and are particularly relevant to understanding proton transfer reactions that directly involve transition metal centres.

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“…The exceptional tolerance of Re MBH to O 2 (10) inspired us to assess its electrocatalytic activity under extremely demanding conditions, including the presence of CO, which is the classic inhibitor of hydrogen-cycling catalysts (11). This inhibition is rationalized on the basis that activation of H 2 by transition metals requires it to form a bond that involves back donation of d-orbital electron density from the metal into the antibonding orbital of H 2 (12,13). A similar electronic principle is well known to be responsible for the strong binding of -acceptor ligands such as CO and O 2 .…”

mentioning

confidence: 99%

Electrocatalytic hydrogen oxidation by an enzyme at high carbon monoxide or oxygen levels

Vincent

Cracknell

Lenz

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

247

282

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Use of hydrogen in fuel cells requires catalysts that are tolerant to oxygen and are able to function in the presence of poisons such as carbon monoxide. Hydrogen-cycling catalysts are widespread in the bacterial world in the form of hydrogenases, enzymes with unusual active sites composed of iron, or nickel and iron, that are buried within the protein. We have established that the membrane-bound hydrogenase from the ␤-proteobacterium Ralstonia eutropha H16, when adsorbed at a graphite electrode, exhibits rapid electrocatalytic oxidation of hydrogen that is completely unaffected by carbon monoxide [at 0.9 bar (1 bar ‫؍‬ 100 kPa), a 9-fold excess] and is inhibited only partially by oxygen. The practical significance of this discovery is illustrated with a simple fuel cell device, thus demonstrating the feasibility of future hydrogen-cycle technologies based on biological or biologically inspired electrocatalysts having high selectivity for hydrogen.biohydrogen ͉ electron transfer ͉ energy ͉ fuel cell ͉ hydrogenase H ydrogenases prevail throughout the microbial world and are essential to hydrogen metabolism (1). X-ray crystallography in conjunction with Fourier transform infrared spectroscopy has revealed that the active site structure of the [NiFe] hydrogenases from Desulfovibrio gigas (Dg) (2) and D. vulgaris Miyazaki F (3, 4) is a bimetallic site having Ni and Fe centers linked by bridging cysteinyl S, with the Fe additionally coordinated by one CO and two CN Ϫ ligands. Crystallographic experiments on the enzyme from D. fructosovorans involving infusion of Xe have revealed the likely positions of ''gas channels'' for transport of small molecules such as H 2 , O 2 , and CO to and from the active site (5).The vast majority of hydrogenase-containing microorganisms, including the Desulfovibrio species, live under anaerobic or semianaerobic conditions, and like their hosts, the hydrogenases are usually highly sensitive to O 2 (1). However, some bacteria are able to gain energy from H 2 oxidation under aerobic conditions. A well studied example is Ralstonia eutropha (Re, formerly Alcaligenes eutrophus) strain H16 a ␤-proteobacterium that hosts three physiologically distinct [NiFe] hydrogenases (6-8). One of these enzymes, the membrane-bound hydrogenase (MBH), is coupled via a b-type cytochrome to the respiratory chain. Sequence similarity shows that this enzyme belongs to the family of [NiFe] hydrogenases having a large subunit containing the NiOFe catalytic center and a small electron-transferring subunit accommodating three iron-sulfur clusters (9). The MBH enables Re to grow on H 2 as the sole energy source even under ambient levels of O 2 . The exceptional tolerance of Re MBH to O 2 (10) inspired us to assess its electrocatalytic activity under extremely demanding conditions, including the presence of CO, which is the classic inhibitor of hydrogen-cycling catalysts (11). This inhibition is rationalized on the basis that activation of H 2 by transition metals requires it to form a bond that involves back donation ...

show abstract

Coordination chemistry of dihydrogen

Cited by 598 publications

References 40 publications

Nickel hydrogenases: in search of the active site

Nickel hydrogenases: in search of the active site

Hydrogen bonds involving transition metal centres – a brief review

Electrocatalytic hydrogen oxidation by an enzyme at high carbon monoxide or oxygen levels

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