Electrochemical insights into the mechanisms of proton reduction by [Fe2(CO)6{μ-SCH2N(R)CH2S}] complexes related to the [2Fe]H subsite of [FeFe]hydrogenase

被引:93
作者
Capon, Jean-Francois [1 ]
Ezzaher, Salah [1 ]
Gloaguen, Frederic [1 ]
Petillon, Francois Y. [1 ]
Schollhammer, Philippe [1 ]
Talarmin, Jean [1 ]
机构
[1] Univ Bretagne Occidentale, CNRS, UMR 6521, Chim Electrochim Mol & Chim Analyt, F-29285 Brest, France
关键词
bioinorganic chemistry; electrochemistry; iron; proton reduction; S ligands;
D O I
10.1002/chem.200701454
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Electrochemical investigations on a structural analogue of the [2Fe](H) subsite of [FeFe]H-2 ases, namely, [Fe-2(CO)(6){mu-SCH2N(CH2CH2OCH3)CH2S}] (1), were conducted in MeCN/NBu4PF6 in the presence of HBF4/Et2O or HOTS. Two different catalytic proton reduction processes operate, depending on the strength and the concentration of the acid used. The first process, which takes place around -1.2 V for both HBF4/Et2O and HOTS, is limited by the slow release of H-2 from the product of the {2H(+)/2e} pathway, 1-2H. The second catalytic process, which occurs at higher acid concentrations, takes place at different potentials depending on the acid present. We propose that this second mechanism is initiated by protonation of 1-2H when HBF4/Et2O is used, whereas the reduction of 1-2H is the initial step in the presence of the weaker acid HOTS. The potential of the second process, which occurs around -1.4V (reduction potential of 1-3H(+)) or around -1.6V (the reduction potential of 1-2H) is thus dependent on the strength of the available proton source.
引用
收藏
页码:1954 / 1964
页数:11
相关论文
共 103 条
  • [11] Electrochemical and theoretical investigations of the reduction of [Fe2(CO)5L{μ-SCH2XCH2S}] complexes related to [FeFe] hydrogenase
    Capon, Jean-Francois
    Ezzaher, Salah
    Gloaguen, Frederic
    Petillon, Francois Y.
    Schollhammer, Philippe
    Talarmin, Jean
    Davin, Thomas J.
    McGrady, John E.
    Muir, Kenneth W.
    [J]. NEW JOURNAL OF CHEMISTRY, 2007, 31 (12) : 2052 - 2064
  • [12] Catalysis of the electrochemical H2 evolution by di-iron sub-site models
    Capon, JF
    Gloaguen, F
    Schollhammer, P
    Talarmin, J
    [J]. COORDINATION CHEMISTRY REVIEWS, 2005, 249 (15-16) : 1664 - 1676
  • [13] N-heterocyclic carbene ligands as cyanide mimics in diiron models of the all-iron hydrogenase active site
    Capon, JF
    El Hassnaoui, S
    Gloaguen, F
    Schollhammer, P
    Talarmin, J
    [J]. ORGANOMETALLICS, 2005, 24 (09) : 2020 - 2022
  • [14] CHANTOONI MK, 1970, J AM CHEM SOC, V92, P2236
  • [15] Electrocatalytic proton reduction by phosphido-bridged diiron carbonyl compounds: Distant relations to the H-cluster?
    Cheah, MH
    Borg, SJ
    Bondin, MI
    Best, SP
    [J]. INORGANIC CHEMISTRY, 2004, 43 (18) : 5635 - 5644
  • [16] Steps along the path to dihydrogen activation at [FeFe] hydrogenase structural models: Dependence of the core geometry on electrocatalytic proton reduction
    Cheah, Mun Hon
    Borg, Stacey J.
    Best, Stephen P.
    [J]. INORGANIC CHEMISTRY, 2007, 46 (05) : 1741 - 1750
  • [17] Electrocatalysis of hydrogen production by active site analogues of the iron hydrogenase enzyme: structure/function relationships
    Chong, DS
    Georgakaki, IP
    Mejia-Rodriguez, R
    Samabria-Chinchilla, J
    Soriaga, MP
    Darensbourg, MY
    [J]. DALTON TRANSACTIONS, 2003, (21) : 4158 - 4163
  • [18] RELATIVE BASICITIES OF NITRILES, ACETONE, AND WATER AS SOLVENTS
    COETZEE, JF
    MCGUIRE, DK
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1963, 67 (09) : 1810 - &
  • [19] A new intermolecular interaction: Unconventional hydrogen bonds with element-hydride bonds as proton acceptor
    Crabtree, RH
    Siegbahn, PEM
    Eisenstein, O
    Rheingold, AL
    [J]. ACCOUNTS OF CHEMICAL RESEARCH, 1996, 29 (07) : 348 - 354
  • [20] Substrate binding and activation via pendant hydrogen-bonding groups as an approach to biomimetic homogeneous catalysis
    Crabtree, RH
    Loch, JA
    Gruet, K
    Lee, DH
    Borgmann, C
    [J]. JOURNAL OF ORGANOMETALLIC CHEMISTRY, 2000, 600 (1-2) : 7 - 11