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Cooperativity between low-valent iron and potassium promoters in dinitrogen fixation.

ABSTRACT: A density functional theory (DFT) study was performed to understand the role of cooperativity between iron-?-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 N(3-) 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-à-vis N(2) activation upon the inclusion of solvent effects.

SUBMITTER: Figg TM

PROVIDER: S-EPMC3398193 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature

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Cooperativity between low-valent iron and potassium promoters in dinitrogen fixation.

Figg Travis M TM Holland Patrick L PL Cundari Thomas R TR

Inorganic chemistry 20120626 14

A density functional theory (DFT) study was performed to understand the role of cooperativity between iron-β-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 N(3-) ligand formed upon N(2) scission, thus making the activated iron nitride complex more energetically accessible. Reduction of the complex ...[more]

PMID: 22734966

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