8 results on '"Zhao, Jiyong"'
Search Results
2. Effects of Noncovalent Interactions on High-Spin Fe(IV)–Oxido Complexes
- Author
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Oswald, Victoria F, Lee, Justin L, Biswas, Saborni, Weitz, Andrew C, Mittra, Kaustuv, Fan, Ruixi, Li, Jikun, Zhao, Jiyong, Hu, Michael Y, Alp, Esen E, Bominaar, Emile L, Guo, Yisong, Green, Michael T, Hendrich, Michael P, and Borovik, AS
- Subjects
Density Functional Theory ,Iron Compounds ,Lewis Acids ,Molecular Conformation ,Oxides ,Chemical Sciences ,General Chemistry - Abstract
High-valent nonheme FeIV-oxido species are key intermediates in biological oxidation, and their properties are proposed to be influenced by the unique microenvironments present in protein active sites. Microenvironments are regulated by noncovalent interactions, such as hydrogen bonds (H-bonds) and electrostatic interactions; however, there is little quantitative information about how these interactions affect crucial properties of high valent metal-oxido complexes. To address this knowledge gap, we introduced a series of FeIV-oxido complexes that have the same S = 2 spin ground state as those found in nature and then systematically probed the effects of noncovalent interactions on their electronic, structural, and vibrational properties. The key design feature that provides access to these complexes is the new tripodal ligand [poat]3-, which contains phosphinic amido groups. An important structural aspect of [FeIVpoat(O)]- is the inclusion of an auxiliary site capable of binding a Lewis acid (LAII); we used this unique feature to further modulate the electrostatic environment around the Fe-oxido unit. Experimentally, studies confirmed that H-bonds and LAII s can interact directly with the oxido ligand in FeIV-oxido complexes, which weakens the Fe═O bond and has an impact on the electronic structure. We found that relatively large vibrational changes in the Fe-oxido unit correlate with small structural changes that could be difficult to measure, especially within a protein active site. Our work demonstrates the important role of noncovalent interactions on the properties of metal complexes, and that these interactions need to be considered when developing effective oxidants.
- Published
- 2020
3. Structural characterization of a non-heme iron active site in zeolites that hydroxylates methane
- Author
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Snyder, Benjamin E. R., Böttger, Lars H., Bols, Max L., Yan, James J., Rhoda, Hannah M., Jacobs, Ariel B., Hu, Michael Y., Zhao, Jiyong, Alp, E. Ercan, Hedman, Britt, Hodgson, Keith O., Schoonheydt, Robert A., Sels, Bert F., and Solomon, Edward I.
- Published
- 2018
4. NRVS definition of O2 intermediates in an extradiol dioxygenase: correlation to crystallography and reactivity
- Author
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Sutherlin, Kyle D., Wasada-Tsutsui, Yuko, Mbughuni, Michael M., Rogers, Melanie S., Park, Kiyoung, Liu, Lei V., Kwak, Yeonju, Srnec, Martin, Böttger, Lars H., Frenette, Mathieu, Yoda, Yoshitaka, Kobayashi, Yasuhiro, Kurokuzu, Masayuki, Saito, Makina, Seto, Makoto, Hu, Michael, Zhao, Jiyong, Alp, E. Ercan, Lipscomb, John D., and Solomon, Edward I.
- Subjects
Molecular Structure ,Iron ,Spectrum Analysis ,Catechols ,Crystallography, X-Ray ,Vibration ,Article ,Dioxygenases ,Oxygen ,Bacterial Proteins ,Models, Chemical ,Coordination Complexes ,Mutation ,Brevibacterium ,Histidine ,Density Functional Theory - Abstract
The extradiol dioxygenases are a large subclass of mononuclear non-heme Fe enzymes that catalyze the oxidative cleavage of catechols distal to their OH groups. These enzymes are important in bioremediation, and there has been significant interest in understanding how they activate O(2). The extradiol dioxygenase homoprotocatechuate 2,3-dioxygenase (HPCD) provides an opportunity to study this process, as two O(2) intermediates have been trapped and crystallographically defined using the slow substrate 4-nitrocatechol (4NC): a side-on Fe-O(2)-4NC species and a Fe-O(2)-4NC peroxy bridged species. Also with 4NC, two solution intermediates have been trapped in the H200N variant, where H200 provides a second-sphere hydrogen bond in the wild-type enzyme. While the electronic structure of these solution intermediates has been defined previously as Fe(III)-superoxo-catecholate and Fe(III)-peroxysemiquinone, their geometric structures are unknown. Nuclear resonance vibrational spectroscopy (NRVS) is an important tool for structural definition of non-heme Fe-O(2) intermediates, as all normal modes with Fe displacement have intensity in the NRVS spectrum. In this study, NRVS is used to define the geometric structure of the H200N-4NC solution intermediates in HPCD as an end-on Fe(III)-superoxocatecholate and an end-on Fe(III)-hydroperoxo-semiquinone. Parallel calculations are performed to define the electronic structures and protonation states of the crystallographically defined wild-type HPCD-4NC intermediates, where the side-on intermediate is found to be a Fe(III)-hydroperoxo-semiquinone. The assignment of this crystallographic intermediate is validated by correlation to the NRVS data through computational removal of H200. While the side-on hydroperoxo semiquinone intermediate is computationally found to be nonreactive in peroxide bridge formation, it is isoenergetic with a superoxo catecholate species that is competent in performing this reaction. This study provides insight into the relative reactivities of Fe(III)-superoxo and Fe(III)-hydroperoxo intermediates in non-heme Fe enzymes and into the role H200 plays in facilitating extradiol catalysis.
- Published
- 2018
5. Exploring the Vibrational Side of Spin‐Phonon Coupling in Single‐Molecule Magnets via 161Dy Nuclear Resonance Vibrational Spectroscopy.
- Author
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Scherthan, Lena, Pfleger, Rouven F., Auerbach, Hendrik, Hochdörffer, Tim, Wolny, Juliusz A., Bi, Wenli, Zhao, Jiyong, Hu, Michael Y., Alp, E. Ercan, Anson, Christopher E., Diller, Rolf, Powell, Annie K., and Schünemann, Volker
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SINGLE molecule magnets ,RESONANCE ,SPECTROMETRY ,DENSITY functional theory ,DENSITY of states ,SYNCHROTRONS - Abstract
Synchrotron‐based nuclear resonance vibrational spectroscopy (NRVS) using the Mössbauer isotope 161Dy has been employed for the first time to study the vibrational properties of a single‐molecule magnet (SMM) incorporating DyIII, namely [Dy(Cy3PO)2(H2O)5]Br3⋅2 (Cy3PO)⋅2 H2O ⋅2 EtOH. The experimental partial phonon density of states (pDOS), which includes all vibrational modes involving a displacement of the DyIII ion, was reproduced by means of simulations using density functional theory (DFT), enabling the assignment of all intramolecular vibrational modes. This study proves that 161Dy NRVS is a powerful experimental tool with significant potential to help to clarify the role of phonons in SMMs. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
6. Moment‐Volume Coupling in La(Fe1<italic>−x</italic>Si<italic>x</italic>)13.
- Author
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Gruner, Markus E., Keune, Werner, Landers, Joachim, Salamon, Soma, Krautz, Maria, Zhao, Jiyong, Hu, Michael Y., Toellner, Thomas, Alp, Esen E., Gutfleisch, Oliver, and Wende, Heiko
- Subjects
MAGNETIC moments ,MAGNETIC coupling ,MAGNETOSTRICTION ,MAGNETOCALORIC effects ,GROUND state (Quantum mechanics) - Abstract
We investigate the origin of the volume change and magnetoelastic interaction observed at the magnetic first‐order transition in the magnetocaloric system La(Fe
1− Six )x 13 by means of first‐principles calculations combined with the fixed‐spin moment approach. We find that the volume of the system varies with the square of the average local Fe moment, which is significantly smaller in the spin disordered configurations compared to the ferromagnetic ground state. The vibrational density of states obtained for a hypothetical ferromagnetic state with artificially reduced spin‐moments compared to a nuclear inelastic X‐ray scattering measurement directly above the phase transition reveals that the anomalous softening at the transition essentially depends on the same moment‐volume coupling mechanism. In the same spirit, the dependence of the average local Fe moment on the Si content can account for the occurence of first‐ and second‐order transitions in the system. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
7. Nitrosylation of Nitric-Oxide-Sensing Regulatory Proteins Containing [4Fe-4S] Clusters Gives Rise to Multiple Iron-Nitrosyl Complexes.
- Author
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Serrano, Pauline N., Wang, Hongxin, Crack, Jason C., Prior, Christopher, Hutchings, Matthew I., Thomson, Andrew J., Kamali, Saeed, Yoda, Yoshitaka, Zhao, Jiyong, Hu, Michael Y., Alp, Ercan E., Oganesyan, Vasily S., Le Brun, Nick E., and Cramer, Stephen P.
- Subjects
IRON-sulfur proteins ,NITRIC oxide ,NITROSYL compounds ,DENSITY functional theory ,LIGANDS (Chemistry) ,THIOLATES - Abstract
The reaction of protein-bound iron-sulfur (Fe-S) clusters with nitric oxide (NO) plays key roles in NO-mediated toxicity and signaling. Elucidation of the mechanism of the reaction of NO with DNA regulatory proteins that contain Fe-S clusters has been hampered by a lack of information about the nature of the iron-nitrosyl products formed. Herein, we report nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) calculations that identify NO reaction products in WhiD and NsrR, regulatory proteins that use a [4Fe-4S] cluster to sense NO. This work reveals that nitrosylation yields multiple products structurally related to Roussin's Red Ester (RRE, [Fe
2 (NO)4 (Cys)2 ]) and Roussin's Black Salt (RBS, [Fe4 (NO)7 S3 ]. In the latter case, the absence of32 S/34 S shifts in the Fe−S region of the NRVS spectra suggest that a new species, Roussin's Black Ester (RBE), may be formed, in which one or more of the sulfide ligands is replaced by Cys thiolates. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
8. Moment‐Volume Coupling in La(Fe1<italic>−x</italic>Si<italic>x</italic>)13.
- Author
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Gruner, Markus E., Keune, Werner, Landers, Joachim, Salamon, Soma, Krautz, Maria, Zhao, Jiyong, Hu, Michael Y., Toellner, Thomas, Alp, Esen E., Gutfleisch, Oliver, and Wende, Heiko
- Subjects
- *
MAGNETIC moments , *MAGNETIC coupling , *MAGNETOSTRICTION , *MAGNETOCALORIC effects , *GROUND state (Quantum mechanics) - Abstract
We investigate the origin of the volume change and magnetoelastic interaction observed at the magnetic first‐order transition in the magnetocaloric system La(Fe1−
x Six )13 by means of first‐principles calculations combined with the fixed‐spin moment approach. We find that the volume of the system varies with the square of the average local Fe moment, which is significantly smaller in the spin disordered configurations compared to the ferromagnetic ground state. The vibrational density of states obtained for a hypothetical ferromagnetic state with artificially reduced spin‐moments compared to a nuclear inelastic X‐ray scattering measurement directly above the phase transition reveals that the anomalous softening at the transition essentially depends on the same moment‐volume coupling mechanism. In the same spirit, the dependence of the average local Fe moment on the Si content can account for the occurence of first‐ and second‐order transitions in the system. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
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