The factors/structural features which are responsible for the binding, activation and reduction of N₂ to NH₃ by FeMoco of nitrogenase have not been completely understood well. Several relevant model complexes by Holland et al. and Peters et al. have been synthesized, characterized and studied by theoretical calculations. For a matter of fact, those complexes are much different than real active N₂-binding Fe-sites of FeMoco, which possesses a central C(4-) ion having an eight valence electrons as an μ₆-bridge. Here, a series of [(S₃C(0))Fe(II/I/0)-N₂]^n- complexes in different charged/spin states containing a coordinated σ- and π-donor C(0)-atom which possesses eight outer shell electrons [carbone, (Ph₃P)₂C(0); Ph₃P→C(0)←PPh₃] and three S-donor sites (i.e. ^-S-Ar), have been studied by DFT, QTAIM, and EDA-NOCV calculations. The effect of the weak field ligand on Fe-centres and the subsequent N₂-binding has been studied by EDA-NOCV analysis. The role of the oxidation state of Fe and N₂-binding in different charged and spin states of the complex have been investigated by EDA-NOCV analyses. The intrinsic interaction energies of the Fe−N₂ bond are in the range from −42/−35 to −67 kcal/mol in their corresponding ground states. The S₃C(0) donor set is argued here to be closer to the actual coordination environment of one of the six Fe-centres of nitrogenase. In comparison, the captivating model complexes reported by Holland et al. and Peter et al. possess a stronger π-acceptor C-ring (S₂C_ring donor, π-C donor) and stronger donor set like CP₃ (σ-C donor) ligands, respectively.

中文翻译：

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与固氮酶辅因子相关的碳 (0)-铁-N2 复合物的稳定性和键合：EDA-NOCV 分析

负责固氮酶的 FeMoco 将 N ₂结合、激活和还原为 NH ₃的因素/结构特征尚未完全清楚。Holland 等人的几个相关模型复合体。和彼得斯等人。已通过理论计算合成、表征和研究。事实上，这些复合物与 FeMoco 的真正活性 N ₂结合 Fe 位点有很大不同，FeMoco 具有中心 C(4-) 离子，该离子具有八个价电子作为 μ ₆ -桥。这里，一系列 [(S ₃ C(0))Fe(II/I/0)-N ₂ ] ^n-不同带电/自旋态的复合物，包含配位的 σ- 和 π- 供体 C(0)-原子，该原子具有八个外壳电子 [carbone, (Ph ₃ P) ₂ C(0)；Ph ₃ P→C(0)←PPh ₃ ] 和三个 S 供体位点（即^- S-Ar）已通过 DFT、QTAIM 和 EDA-NOCV 计算进行了研究。已通过 EDA-NOCV 分析研究了弱场配体对 Fe 中心和随后的 N ₂结合的影响。_{已通过 EDA-NOCV 分析研究了 Fe 和 N 2}结合的氧化态在复合物的不同带电和自旋态中的作用。Fe−N _{2的固有相互作用能}键在它们相应的基态下在-42/-35 到-67 kcal/mol 的范围内。S ₃ C(0) 供体集在这里被认为更接近固氮酶六个 Fe 中心之一的实际配位环境。相比之下，Holland 等人报道的迷人模型复合体。和彼得等人。分别拥有更强的π受体C环（S ₂ C_环供体，π-C供体）和更强的供体组如CP ₃（σ-C供体）配体。