Density functional calculations on the binding of dinitrogen to the FeFe cofactor in Fe-only nitrogenase: FeFeCo(mu(6)-N-2) as intermediate in nitrogen fixation

作者：Cao, ZX^*; Zhou, ZH; Wan, HL; Zhang, Q; Thiel, W

来源：Inorganic Chemistry, 2003, 42(22): 6986-6988.

DOI：10.1021/ic034714x

• CENTRAL LIGAND
• MOLYBDENUM NITROGENASE
• CARBON-MONOXIDE
• MOFE-PROTEIN
• ACTIVE-SITE
• CLUSTER
• ENERGY
• ENDOR
• PSEUDOPOTENTIALS
• RESOLUTION

The geometries and stabilities of the FeFe cofactor at different oxidation states and its complexes with N-2 have been determined by density functional calculations. These calculations support an EPR-inactive resting state of the FeFe cofactor with four Fe2+ and four Fe3+ sites (4Fe(2+)4Fe(3+)). FeFeco(mu(6)-N-2) with a central dinitrogen ligand is predicted to be the most stable complex of the FeFe cofactor with N-2. It is easily formed by penetration of N-2 into the trigonal Fe-6 prism of the FeFe cofactor with an approximate barrier of 4 kcal mol(-1). The present DFT results suggest that an FeFeco(mu(6)-N-2) entity is a plausible intermediate in dinitrogen fixation by nitrogenase. CO is calculated to bind even more strongly than N-2 to the FeFe cofactor so that CO may inhibit the reduction of nitrogen by Fe-only nitrogenase.

• 出版日期2003-11-3
• 单位厦门大学