Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Characterization of a Ferryl Flip in Electronically Tuned Nonheme Complexes. Consequences in Hydrogen Atom Transfer Reactivity
Ist Teil von
Angewandte Chemie, 2023-01, Vol.135 (2), p.n/a
Ort / Verlag
Weinheim: Wiley Subscription Services, Inc
Erscheinungsjahr
2023
Quelle
Wiley Online Library All Journals
Beschreibungen/Notizen
Two oxoiron(IV) isomers (R2a and R2b) of general formula [FeIV(O)(RPyNMe3)(CH3CN)]2+ are obtained by reaction of their iron(II) precursor with NBu4IO4. The two isomers differ in the position of the oxo ligand, cis and trans to the pyridine donor. The mechanism of isomerization between R2a and R2b has been determined by kinetic and computational analyses uncovering an unprecedented path for interconversion of geometrical oxoiron(IV) isomers. The activity of the two oxoiron(IV) isomers in hydrogen atom transfer (HAT) reactions shows that R2a reacts one order of magnitude faster than R2b, which is explained by a repulsive noncovalent interaction between the ligand and the substrate in R2b. Interestingly, the electronic properties of the R substituent in the ligand pyridine ring do not have a significant effect on reaction rates. Overall, the intrinsic structural aspects of each isomer define their relative HAT reactivity, overcoming changes in electronic properties of the ligand.
The isomerization of pairs of electronically tuned oxoiron(IV) geometrical isomers is described, as a model for the “ferryl flip” observed in non‐heme enzymes. The position of the oxo ligand in the coordination sphere of the iron center has a strong impact on the hydrogen‐atom transfer (HAT) activity of the oxoiron(IV) compounds, while electronic effects do not play a significant role in HAT reactions.