The effects of redox state and ligand characteristics on structural, electronic, and reactivity properties of complexes related to the [2Fe](H) subcluster of [Fe]-hydrogenases have been investigated by DFT calculations and compared with experimental and theoretical data obtained investigating both the enzyme and synthetic model complexes. Our results show that (FeFeII)-Fe-II species characterized by OH or H2O groups terminally coordinated to the iron atom distal to the terminal sulfur ligand (Fe-d) are less stable than corresponding mu-OH or mu-H2O species, suggesting that the latter are destabilized or kinetically inaccessible in the enzyme. In addition, results obtained investigating (FeFeI)-Fe-I and (FeFeI)-Fe-II complexes show that structure and relative stability of species characterized by a mu-CO group are significantly affected by the electronic properties of the ligands coordinated to the iron atoms. The investigation of reaction pathways for H-2 activation confirms and extends a previous hypothesis indicating that H-2 can be cleaved on (FeFeII)-Fe-II species. In particular, even though [Fe]-hydrogenases are proposed to bind and activate H-2 at a single iron center, the comparison of our data with experimental results obtained studying synthetic complexes (Zhao, X.; Georgakaki, I. P.; Miller, M. L.; Mejia-Rodriguez, R.; Chiang, C.-Y.; Darensbourg, M. Y. Inorg. Chem. 2002, 41, 3917) suggests that activation paths involving both metal ions are also possible. Moreover, p-H (FeFeI)-Fe-II complexes are predicted to correspond to stable species and might be formed in the enzyme catalytic cycle

Bruschi, M., Fantucci, P., De Gioia, L. (2003). Density functional theory investigation of the active site of [Fe]-hydrogenases: Effects of redox state and ligand characteristics on structural, electronic, and reactivity properties of complexes related to the [2Fe](H) subcluster. INORGANIC CHEMISTRY, 42(15), 4773-4781 [10.1021/ic0262132].

Density functional theory investigation of the active site of [Fe]-hydrogenases: Effects of redox state and ligand characteristics on structural, electronic, and reactivity properties of complexes related to the [2Fe](H) subcluster

Bruschi, M;Fantucci, P;De Gioia, L.
2003

Abstract

The effects of redox state and ligand characteristics on structural, electronic, and reactivity properties of complexes related to the [2Fe](H) subcluster of [Fe]-hydrogenases have been investigated by DFT calculations and compared with experimental and theoretical data obtained investigating both the enzyme and synthetic model complexes. Our results show that (FeFeII)-Fe-II species characterized by OH or H2O groups terminally coordinated to the iron atom distal to the terminal sulfur ligand (Fe-d) are less stable than corresponding mu-OH or mu-H2O species, suggesting that the latter are destabilized or kinetically inaccessible in the enzyme. In addition, results obtained investigating (FeFeI)-Fe-I and (FeFeI)-Fe-II complexes show that structure and relative stability of species characterized by a mu-CO group are significantly affected by the electronic properties of the ligands coordinated to the iron atoms. The investigation of reaction pathways for H-2 activation confirms and extends a previous hypothesis indicating that H-2 can be cleaved on (FeFeII)-Fe-II species. In particular, even though [Fe]-hydrogenases are proposed to bind and activate H-2 at a single iron center, the comparison of our data with experimental results obtained studying synthetic complexes (Zhao, X.; Georgakaki, I. P.; Miller, M. L.; Mejia-Rodriguez, R.; Chiang, C.-Y.; Darensbourg, M. Y. Inorg. Chem. 2002, 41, 3917) suggests that activation paths involving both metal ions are also possible. Moreover, p-H (FeFeI)-Fe-II complexes are predicted to correspond to stable species and might be formed in the enzyme catalytic cycle
Articolo in rivista - Articolo scientifico
Fe-only hydrogenase; heterolytic cleveage; iron; coordination
English
2003
42
15
4773
4781
none
Bruschi, M., Fantucci, P., De Gioia, L. (2003). Density functional theory investigation of the active site of [Fe]-hydrogenases: Effects of redox state and ligand characteristics on structural, electronic, and reactivity properties of complexes related to the [2Fe](H) subcluster. INORGANIC CHEMISTRY, 42(15), 4773-4781 [10.1021/ic0262132].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/3701
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