Synthetic Models of the Active Site of Cytochrome <i>c</i> Oxidase: Influence of Tridentate or Tetradentate Copper Chelates Bearing a HisTyr Linkage Mimic on Dioxygen Adduct Formation by Heme/Cu Complexes

Liu, Jin Gang; Naruta, Yoshinori; Tani, Fumito

doi:10.1002/chem.200601884

Cited by 28 publications

(27 citation statements)

References 75 publications

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“…Among both high-spin and low-spin synthetic model complexes compiled from 15 reports in the literature, a Cu–O stretch has been observed in only three LS species out of 24 HS and LS complexes 36,39,45,46,48,53,55,56,59,70–75. Further, of those three, only one employed a copper ligand that was not TMPA (the other two being the HS and LS parent TMPA complexes) 36,59,72. Thus, this report more than doubles the description and characterization of known synthetic low-spin heme–peroxo–copper complexes in the literature, with 8 newly prepared species.…”

Section: Resultsmentioning

confidence: 75%

Influence of intramolecular secondary sphere hydrogen-bonding interactions on cytochrome c oxidase inspired low-spin heme–peroxo–copper complexes

et al. 2019

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Section: Resultsmentioning

confidence: 75%

Influence of intramolecular secondary sphere hydrogen-bonding interactions on cytochrome c oxidase inspired low-spin heme–peroxo–copper complexes

et al. 2019

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“…In fact, this high-energy O–O stretching frequency may imply the presence of the μ -η 2 :η 1 peroxo binding mode, as observed in analogous complexes with tetradentate copper chelates discussed above. 935…”

Section: Small Molecule Synthetic Models Of Heme-copper Oxidasesmentioning

confidence: 99%

“…(A) [(TMP)Fe III -(O 2 2– )-Cu II (L N3OH )] + and (B) [(TMP)Fe III -(O 2 2– )-Cu n (L N3-ONa )] + . 935 .…”

Section: Figurementioning

confidence: 99%

Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function

et al. 2018

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Heme-copper oxidases (HCOs) are terminal enzymes on the mitochondrial or bacterial respiratory electron transport chain, which utilize a unique heterobinuclear active site to catalyze the 4H+/4e− reduction of dioxygen to water. This process involves a proton-coupled electron transfer (PCET) from a tyrosine (phenolic) residue and additional redox events coupled to transmembrane proton pumping and ATP synthesis. Given that HCOs are large, complex, membrane-bound enzymes, bioinspired synthetic model chemistry is a promising approach to better understand heme-Cu-mediated dioxygen reduction, including the details of proton and electron movements. This review encompasses important aspects of heme-O2 and copper–O2 (bio)chemistries as they relate to the design and interpretation of small molecule model systems and provides perspectives from fundamental coordination chemistry, which can be applied to the understanding of HCO activity. We focus on recent advancements from studies of heme–Cu models, evaluating experimental and computational results, which highlight important fundamental structure–function relationships. Finally, we provide an outlook for future potential contributions from synthetic inorganic chemistry and discuss their implications with relevance to biological O2-reduction.

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“…Such factors have been shown or are expected to dictate the absence or presence of further reactivity, and the nature of such reactivity in the context of O-O cleavage chemistry. With similar emphases, in part, the research groups of Collman and coworkers5,19 and Naruta and coworkers20,21 have been very active and have made major contributions. Collman has also presented a longtime program in biomimetic electrode surface electrocatalysis of the four-electron O 2 -reduction to water 5,22,23.…”

Section: Introductionmentioning

confidence: 95%

Heme−Copper−Dioxygen Complexes: Toward Understanding Ligand-Environmental Effects on the Coordination Geometry, Electronic Structure, and Reactivity

et al. 2010

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The nature of the ligand is an important aspect of controlling structure and reactivity in coordination chemistry. In connection with our study of heme/copper/oxygen reactivity relevant to cytochrome c oxidase O 2 -reduction chemistry, we compare the molecular and electronic structure of two highspin heme-peroxo-copper [Fe III -O 2 2--Cu II ] + complexes containing N 4 -tetradentate (1) or N 3 -tridentate (2) copper ligands. Combining previously reported and new resonance Raman and EXAFS data coupled to DFT calculations we report a geometric structure and more complete electronic description of the high-spin heme-peroxo-copper complexes 1 and 2, which establish μ-(O 2 2-) sideon to the Fe III and end-on to Cu II (μ-η 2 :η 1 ) binding for the complex 1 but side-on/side-on (μ-η 2 :η 2 ) μ-peroxo coordination for the complex 2. We also compare and summarize the differences and similarities of these two complexes in their reactivity toward CO, PPh 3 , acid and phenols. The comparison of a new X-ray structure of μ-oxo complex 2a with the previously reported 1a X-ray structure, two thermal decomposition products respectively of 2 and 1, reveals a considerable difference in the Fe-O-Cu angle between the two μ-oxo complexes (∠Fe-O-Cu = 178.2° in 1a, ∠Fe-O-Cu = 149.5° in 2a). The reaction of 2 with one equivalent of exogenous N-donor axial base leads to the formation of a distinctive low-temperature stable, low-spin heme-O 2 -Cu complex (2b), but under the same conditions the addition of an axial base to 1 leads to the dissociation of the hemeperoxo-Cu assembly and the release of O 2 . 2b reacts with phenols performing hydrogen-atom (e -+ H + ) abstraction resulting in O-O bond cleavage and the formation of high-valent ferryl [Fe IV =O] complex (2c). The nature of 2c was confirmed by comparison of its spectroscopic features and reactivity with those of an independently prepared ferryl complex. The phenoxyl radical generated by the hydrogen-atom abstraction was either 1) directly detected by EPR spectroscopy using phenols that produce stable radicals or 2) indirectly by detection of the coupling product of two phenoxyl radicals.karlin@jhu.edu, edward.solomon@stanford.edu. Supporting Information Available. UV-visible spectra of the reaction of (2b) with 1 equiv. of 2,4-di-tertbutylphenol ( Figure S1), UVvis spectra of the reaction of [(F 8 )Fe III -(O 2 2-)-Cu II (TMPA)] + (1) with DMAP ( Figure S2), EPR spectra of (2b) reaction with 1 equiv.of 2,4-di-tert-butylphenol ( Figure S3), GC-MS trace of the oxidative coupling of 2,4-di-tert-butylphenol in presence of (2b) ( Figure S4), ORTEP diagram ( Figure S5) and crystal data and structure refinement for [(F 8 )Fe III -(O 2-)-Cu II (AN)] + (2a) X-ray structure (Table S1), XAS spectra and computational data.NIH Public Access

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Synthetic Models of the Active Site of Cytochrome c Oxidase: Influence of Tridentate or Tetradentate Copper Chelates Bearing a HisTyr Linkage Mimic on Dioxygen Adduct Formation by Heme/Cu Complexes

Cited by 28 publications

References 75 publications

Influence of intramolecular secondary sphere hydrogen-bonding interactions on cytochrome c oxidase inspired low-spin heme–peroxo–copper complexes

Influence of intramolecular secondary sphere hydrogen-bonding interactions on cytochrome c oxidase inspired low-spin heme–peroxo–copper complexes

Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function

Heme−Copper−Dioxygen Complexes: Toward Understanding Ligand-Environmental Effects on the Coordination Geometry, Electronic Structure, and Reactivity

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