ENDOR Characterization of (N₂)Fe^II(μ-H)₂Fe^I(N₂)^-: A Spectroscopic Model for N₂ Binding by the Di-μ-hydrido Nitrogenase Janus Intermediate.

ABSTRACT: The biomimetic diiron complex 4-(N₂)₂, featuring two terminally bound Fe-N₂ centers bridged by two hydrides, serves as a model for two possible states along the pathway by which the enzyme nitrogenase reduces N₂. One is the Janus intermediate E₄(4H), which has accumulated 4[e-/H+], stored as two [Fe-H-Fe] bridging hydrides, and is activated to bind and reduce N₂ through reductive elimination (RE) of the hydride ligands as H₂. The second is a possible RE intermediate. ¹H and ¹⁴N 35 GHz ENDOR measurements confirm that the formally Fe(II)/Fe(I) 4-(N₂)₂ complex exhibits a fully delocalized, Robin-Day type-III mixed valency. The two bridging hydrides exhibit a fully rhombic d

SUBMITTER: Yang H 

PROVIDER: S-EPMC6649688 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature