Cooperativity Between Low-Valent Iron and Potassium Promoters in Dinitrogen Fixation

作者：Figg Travis M; Holland Patrick L^*; Cundari Thomas R

来源：Inorganic Chemistry, 2012, 51(14): 7546-7550.

DOI：10.1021/ic300150u

A density functional theory (DFT) study was performed to understand the role of cooperativity between iron-beta-diketiminate fragments and potassium promoters in N-2 activation. Sequential addition of iron fragments to N-2 reveals that a minimum of three Fe centers interact with N-2 in order to break the triple bond. The potassium promoter stabilizes the N3- ligand formed upon N-2 scission, thus making the activated iron nitride complex more energetically accessible. Reduction of the complex and stabilization of N-3 by K+ have similar impact on the energetics in the gas phase. However, upon inclusion of continuum THF solvent effects, coordination of K+ has a reduced influence upon the overall energetics of dinitrogen fixation; thus, reduction of the trimetallic Fe complex becomes more impactful than coordination of K+ vis-a-vis N-2 activation upon the inclusion of solvent effects.

• 出版日期2012-7-16