Nuclear Resonance Vibrational Spectroscopy on the FeIVO S=2 Non‐Heme Site in TMG3tren: Experimentally Calibrated Insights into Reactivity

Wong, Shaun D.; Bell, Caleb B.; Liu, Lei V.; Kwak, Yeonju; England, Jason; Ercan, E.; Zhao, Jiyong; Que, Lawrence; Solomon, Edward I.

doi:10.1002/ange.201007692

Cited by 14 publications

(7 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, the energy gap between p* xy and s* x 2 Ày 2 is wider in hexacoordinated metal complexes as compared to pentacoordinated complexes. As a result of that spectroscopic studies on a trigonal bipyramidal iron(IV)-oxo spe- www.chemeurj.org cies give these species as either intermediate (triplet) or high spin state, [23] dependent on the ligand system.…”

Section: Resultsmentioning

confidence: 96%

“…[20] Thus, in octahedral symmetry the 3d xy atomic orbital cannot interact with orbitals in the xy plane and hence is nonbonding (d xy ). As a result of that spectroscopic studies on a trigonal bipyramidal iron(IV)-oxo spe- www.chemeurj.org cies give these species as either intermediate (triplet) or high spin state, [23] dependent on the ligand system. The s* orbitals of [M IV (O)A C H T U N G T R E N N U N G (H 3 buea)] À are high in energy and virtual and look similar in shape and appearance to those calculated before for nonheme metal-oxo complexes.…”

Section: Full Papermentioning

confidence: 96%

See 1 more Smart Citation

Does Hydrogen‐Bonding Donation to Manganese(IV)–Oxo and Iron(IV)–Oxo Oxidants Affect the Oxygen‐Atom Transfer Ability? A Computational Study

Latifi

Sainna

Rybak‐Akimova

et al. 2013

Chemistry A European J

View full text Add to dashboard Cite

Iron(IV)-oxo intermediates are involved in oxidations catalyzed by heme and nonheme iron enzymes, including the cytochromes P450. At the distal site of the heme in P450 Compound I (Fe(IV) -oxo bound to porphyrin radical), the oxo group is involved in several hydrogen-bonding interactions with the protein, but their role in catalysis is currently unknown. In this work, we investigate the effects of hydrogen bonding on the reactivity of high-valent metal-oxo moiety in a nonheme iron biomimetic model complex with trigonal bipyramidal symmetry that has three hydrogen-bond donors directed toward a metal(IV)-oxo group. We show these interactions lower the oxidative power of the oxidant in reactions with dehydroanthracene and cyclohexadiene dramatically as they decrease the strength of the OH bond (BDEOH ) in the resulting metal(III)-hydroxo complex. Furthermore, the distal hydrogen-bonding effects cause stereochemical repulsions with the approaching substrate and force a sideways attack rather than a more favorable attack from the top. The calculations, therefore, give important new insights into distal hydrogen bonding, and show that in biomimetic, and, by extension, enzymatic systems, the hydrogen bond may be important for proton-relay mechanisms involved in the formation of the metal-oxo intermediates, but the enzyme pays the price for this by reduced hydrogen atom abstraction ability of the intermediate. Indeed, in nonheme iron enzymes, where no proton relay takes place, there generally is no donating hydrogen bond to the iron(IV)-oxo moiety.

show abstract

Section: Resultsmentioning

confidence: 96%

Section: Full Papermentioning

confidence: 96%

Does Hydrogen‐Bonding Donation to Manganese(IV)–Oxo and Iron(IV)–Oxo Oxidants Affect the Oxygen‐Atom Transfer Ability? A Computational Study

Latifi

Sainna

Rybak‐Akimova

et al. 2013

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…All of the vibrational modes that contain significant Fe displacement are observable in NRVS spectra, providing a complementary and more complete set of information relative to rR spectroscopy. NRVS has been successfully applied to mononuclear nonheme Fe(III)-peroxo (27) and Fe(IV)-oxo intermediates (28) and binuclear nonheme Fe(III) 2 -peroxo species (29), providing significant insight into their reactivities.…”

mentioning

confidence: 99%

Nuclear resonance vibrational spectroscopic and computational study of high-valent diiron complexes relevant to enzyme intermediates

Park

Bell

Liu

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

High-valent intermediates of binuclear nonheme iron enzymes are structurally unknown despite their importance for understanding enzyme reactivity. Nuclear resonance vibrational spectroscopy combined with density functional theory calculations has been applied to structurally well-characterized high-valent mono-and di-oxo bridged binuclear Fe model complexes. Low-frequency vibrational modes of these high-valent diiron complexes involving Fe motion have been observed and assigned. These are independent of Fe oxidation state and show a strong dependence on spin state. It is important to note that they are sensitive to the nature of the Fe 2 core bridges and provide the basis for interpreting parallel nuclear resonance vibrational spectroscopy data on the highvalent oxo intermediates in the binuclear nonheme iron enzymes.iron-oxo cores | Fe enzymes C lass Ia ribonucleotide reductase (RR) (1) and soluble methane monooxygenase (sMMO) (2) are members of the class of binuclear nonheme iron enzymes. These have intrigued researchers due to their significance in the development of anticancer drugs (RR) (3) and biofuel catalysts (sMMO) (4) and their varied reactivities using a conserved 2 His/4 carboxylate ligand set. These enzymes use a biFe active site to activate O 2 for hydrogen atom abstraction and hydroxylation via key high-valent intermediates called X (5, 6) and Q (7, 8) in RR and sMMO, respectively.

show abstract

“…The Fe(IV)¼O complex with the TMG 3 tren ligand shows only weak C-H activation reactivity, and in its self-decay pathway, hydroxylation activity occurs which is directed towards the guanidine methyl substituents as observed for their copper analogues [65,67]. The existence and reactivity of the Fe(IV)¼O species with this high oxidation state of the metal centre were confirmed by different analytical methods [68]. These systems function as biomimetic models for an intermediate of nonheme iron (NHFs) enzymes, which are responsible for many C-H bond activations [68].…”

Section: Tris(guanidines)mentioning

confidence: 60%

“…The existence and reactivity of the Fe(IV)¼O species with this high oxidation state of the metal centre were confirmed by different analytical methods [68]. These systems function as biomimetic models for an intermediate of nonheme iron (NHFs) enzymes, which are responsible for many C-H bond activations [68]. Additionally, the Que group synthesised iron (IV) TMG 3 + by electrolytic oxidation.…”

Section: Tris(guanidines)mentioning

confidence: 92%

Guanidine Metal Complexes for Bioinorganic Chemistry and Polymerisation Catalysis

Stanek

Rösener

Metz

et al. 2015

Topics in Heterocyclic Chemistry

View full text Add to dashboard Cite

Guanidines are highly useful ligands which have conquered coordination chemistry within the last 20 years. Their CN 3 moiety allows multiple substitution patterns which enables tailoring them to a large variety of applications, ranging from bioinorganic coordination chemistry via medicinal chemistry to polymerisation catalysis. In bioinorganic chemistry, guanidines gave important stimuli in the modelling of copper type 1, 2 and 3 enzymes. This review provides with a comprehensive overview on complexes which have been reported with neutral guanidine ligands. Peralkylated guanidines as well as bicyclic or more complex guanidine-comprising entities are described in their coordination chemistry with transition and main-group metals. The structural features of the complexes as well as their most prominent features in bioinorganic chemistry or polymerisation catalysis are highlighted. Hereby, the role of the delocalisation of the positive charge within the guanidine unit gained during coordination is discussed in its importance for efficient and robust coordination. The delocalisation within the CN 3 unit can be measured by the structural value ρ which is discussed for numerous systems. The charge delocalisation makes neutral guanidines versatile and efficient for the stabilisation of highly different coordination modes and a large variety of oxidation states.

show abstract

Nuclear Resonance Vibrational Spectroscopy on the Fe^IVO S=2 Non‐Heme Site in TMG₃tren: Experimentally Calibrated Insights into Reactivity

Cited by 14 publications

References 26 publications

Does Hydrogen‐Bonding Donation to Manganese(IV)–Oxo and Iron(IV)–Oxo Oxidants Affect the Oxygen‐Atom Transfer Ability? A Computational Study

Does Hydrogen‐Bonding Donation to Manganese(IV)–Oxo and Iron(IV)–Oxo Oxidants Affect the Oxygen‐Atom Transfer Ability? A Computational Study

Nuclear resonance vibrational spectroscopic and computational study of high-valent diiron complexes relevant to enzyme intermediates

Guanidine Metal Complexes for Bioinorganic Chemistry and Polymerisation Catalysis

Contact Info

Product

Resources

About