Article
Chemistry, Inorganic & Nuclear
Sebastian Eckert, Eric J. Mascarenhas, Rolf Mitzner, Raphael M. Jay, Annette Pietzsch, Mattis Fondell, Vinicius Vaz da Cruz, Alexander Foehlisch
Summary: In this study, the impact of metal-ligand bond formation on the electronic structure of the chelating agent ethylenediaminetetraacetic acid (EDTA) and its iron(III) complex was investigated using resonant inelastic X-ray scattering. Distinct spectroscopic signatures such as frontier orbital distortions, occupation changes, and energy shifts were observed.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Sebastian Eckert, Eric J. Mascarenhas, Rolf Mitzner, Raphael M. Jay, Annette Pietzsch, Mattis Fondell, Vinicius Vaz da Cruz, Alexander Foehlisch
Summary: This study investigates the impact of metal-ligand bond formation on the electronic structure of EDTA using resonant inelastic X-ray scattering, including frontier orbital distortions, occupation changes, and energy shifts.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Chen-Yu Lien, Jan-Niklas Boyn, Sophie W. Anferov, David A. Mazziotti, John S. Anderson
Summary: Magnetic exchange coupling plays a crucial role in molecule-based magnetic materials. The direct exchange coupling between an organic radical and a metal is often stronger than superexchange through diamagnetic ligands. However, predicting the magnitude of the exchange coupling for radical linkers bridging paramagnetic centers remains challenging. This study elucidates the features of organic radicals that govern this parameter, providing insights for designing organic radical ligands for molecular-based magnetic compounds and considering multiple competing factors.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Pingping Huang, Yukihiro Yoshida, Tokutaro Komatsu, Yuiga Nakamura, Kunihisa Sugimoto, Hiroshi Kitagawa
Summary: Proton-coupled electron transfer (PCET) in biochemistry and electrochemistry can be controlled by the cis-trans isomerization of a pi-planar platinum complex, Pt(itsq)2 (itsq1-: o-iminothiosemiquinonate). The two isomers were characterized using single-crystal X-ray diffraction, and the cis-to-trans isomerization was achieved in organic solvents. The proton-electron coupling is greatly influenced by the geometrical configuration compared to metal substitution, as predicted by theoretical calculations.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Daniel P. Harrison, Robin Grotjahn, Masnun Naher, Seyed M. B. H. Ghazvini, Daniel M. Mazzucato, Marcus Korb, Stephen A. Moggach, Colin Lambert, Martin Kaupp, Paul J. Low
Summary: The study shows that the 4-OMe substituent in [{Cp*(dppe)RuC equivalent to C}(2)(mu-1,3-C6H4)](+) mixed-valence complex enhances the ground state electron delocalization and intensity of the IVCT transition. The experimental results and vibrational frequency and TDDFT calculations confirm the findings.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Phan N. Phu, Carlos E. Gutierrez, Subrata Kundu, Dimosthenis Sokaras, Thomas Kroll, Timothy H. Warren, S. Chantal E. Stieber
Summary: X-ray emission spectroscopy (XES) was used to study a series of beta-diketiminate Ni-NO complexes with various NO binding modes and oxidation states. The results showed that XES can distinguish end-on vs side-on NO coordination modes and differences in NO coordination angles of around 10 degrees. Additionally, the utility of XES for characterizing NO intermediates in metalloenzymes, such as Cu nitrite reductase (NiR), was demonstrated. This work highlights the capability of XES in quantifying small molecule activation in enzymes.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Wenyan Zhu, Pingping Zheng, Yaoming Shao, Wenqiang Fang, Haifei Wu, Jianxiao Si
Summary: This study successfully synthesized n-type Mg3Sb2-based thermoelectric materials using a novel method and investigated their structure and properties. It was found that the mixed valence of Ni effectively improved the thermoelectric performance, especially by increasing carrier concentrations and reducing lattice thermal conductivity.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Inorganic & Nuclear
Nozomi Tomioka, Tomoyo Misawa-Suzuki, Hirotaka Nagao
Summary: Azobenzene was immobilized on a ruthenium(II) center with two 2,2'-bipyridine ligands, resulting in the formation of a phenylazophenylato complex. Nitration derivatives were obtained by further reactions with nitric acid, leading to substitution at different positions on the coordinated phenylate group. The cleavage of the azo group on the ruthenium complex yielded a dianilineruthenium(II) complex.
Article
Chemistry, Multidisciplinary
Majed S. Fataftah, Brandon Q. Mercado, Patrick L. Holland
Summary: This article reports two mixed-valent diiron complexes with carbon bridges, and demonstrates the ability of carbon bridges to stabilize the valence delocalized ground states in mixed-valent iron dimers through experimental and computational studies.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Mathematics, Interdisciplinary Applications
Nikita M. Egorov, Ilya V. Sysoev, Vladimir I. Ponomarenko, Marina V. Sysoeva
Summary: This paper proposes a new version of the electronic implementation of the FitzHugh-Nagumo neuron model, as well as a new circuit for synapse. The study provides a better representation of the activation function in biological neurons and investigates various scenarios of oscillation emergence and long living transients.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Materials Science, Multidisciplinary
Xiangang Wan, Vsevolod Ivanov, Giacomo Resta, Ivan Leonov, Sergey Y. Savrasov
Summary: The study investigated the magnetic exchange interactions of the superconductor Nd1-xSrxNiO2 using the density-functional-based LDA+U method and linear-response theory. It was found that hole doping significantly enhances the interlayer exchange coupling, while the Nd-5d states do not affect the magnetic exchange interactions and may not participate in the superconductivity of this compound. The analysis using dynamical mean field theory revealed an underlying Mott insulating state that leads to different quasiparticle band structures upon doping.
Article
Chemistry, Applied
Wenbo Li, Yuheng Li, Zilong Zhang, Peng Gao
Summary: This study explored the potential of lead-free perovskite materials for solar energy conversion by varying the trivalent gold ion and halogen anion in Cs2AuIAuIIII6. 18 new structures with unique properties were discovered, among which Cs2AuSbCl6, Cs2AuInCl6, and Cs2AuBiCl6 are potential candidates for solar cell absorbers with a spectroscopic limited maximum efficiency (SLME) of approximately 30%. The discovery of these new materials provides new insights into solar energy conversion.
JOURNAL OF ENERGY CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Zachary Mathe, Olivia McCubbin Stepanic, Sergey Peredkov, Serena DeBeer
Summary: This study evaluates the potential of P Kβ XES in studying phosphate-containing biomolecules and discusses its application in aqueous solution samples, providing detailed information about the electronic structure of phosphate. The research highlights the importance of non-covalent effects in enzymatic catalysis and emphasizes the potential applications of the technique in studying biological energy conversion.
Article
Chemistry, Inorganic & Nuclear
Penghui Jiang, Xiaofei Yang, Na Cao, Xiaoming Zhu, Fuxing Zhang, Sheng Hua Liu, Ya-Ping Ou
Summary: The synthesis of inorganic-organic mixed-valence systems with different aromatic bridge linkers using ferrocene (Fc)-ethynyl-triarylamine (TAA) compounds was studied. The target compounds were synthesized through Sonogashira cross-coupling reactions and characterized by various methods. The redox and electronic coupling properties of these compounds were investigated, and the experimental results were in line with the theoretical calculations.
INORGANICA CHIMICA ACTA
(2022)
Article
Chemistry, Multidisciplinary
Tamyris T. da Cunha, Cleverton O. C. da Silveira, Vitor M. M. Barbosa, Willian X. C. Oliveira, Eufranio N. da Silva Junior, Fabio F. Ferreira, Emerson F. Pedroso, Cynthia L. M. Pereira
Summary: Three new air-stable coordination compounds containing copper and zinc coordinated with oxamate ligands were successfully synthesized and characterized. These compounds exhibit different crystal structures and magnetic behaviors, with the phenol group in the oxamate ligand leading to distinct hydrogen bond patterns in the crystal packing.
Article
Chemistry, Multidisciplinary
Yao Yang, Rishi G. Agarwal, Phillips Hutchison, Ruben Rizo, Alexander Soudackov, Xinyao Lu, Enrique Herrero, Juan M. Feliu, Sharon Hammes-Schiffer, James M. Mayer, Hector D. Abruna
Summary: This study reveals that Pt(111) exhibits higher ORR activity in D2O compared to H2O, and the inverse kinetic isotope effects (KIEs) are closely related to the coverage and binding strength.
Review
Chemistry, Multidisciplinary
Elsa C. Y. Yan, Ethan A. Perets, Daniel Konstantinovsky, Sharon Hammes-Schiffer
Summary: Chemists have been fascinated by the interplay of chirality, water, and interfaces, and its potential in elucidating biological functions. However, technical challenges have hindered the study of this chemistry. Using chiral SFG, researchers have been able to detect protein folding and DNA structures as well as water behaviors at interfaces. This method shows promise in probing the intricate chemical interplay of chirality, water, and interfaces.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Editorial Material
Chemistry, Multidisciplinary
Michelle L. Personick
Article
Chemistry, Physical
Tao E. Li, Sharon Hammes-Schiffer
Summary: Within the NEO framework, the RT-NEO-TDDFT approach allows simulation of coupled electronic-nuclear dynamics. The BO approximation within this approach enables larger time steps and fixes the unphysical asymmetric Rabi splitting observed in previous simulations. Furthermore, it provides a foundation for various chemical and biological applications.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Mathew Chow, Eleftherios Lambros, Xiaosong Li, Sharon Hammes-Schiffer
Summary: This study introduces a new nuclear-electronic orbital (NEO) QM/MM approach for simulating chemical reactions in atomistic and heterogeneous environments. It allows the quantization of specified nuclei, such as protons, using NEO-density functional theory. The approach considers proton delocalization, polarization, anharmonicity, and zero-point energy in geometry optimizations and dynamics. The study provides expressions for the energies and gradients associated with the NEO-QM/MM method and demonstrates its potential application in solvation and dynamics studies.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Jiayun Zhong, Clorice R. Reinhardt, Sharon Hammes-Schiffer
Summary: Ribonucleotide reductase (RNR) plays a role in regulating DNA synthesis and repair in all organisms. The mechanism of Escherichia coli RNR involves a proton-coupled electron transfer (PCET) pathway spanning across two protein subunits. A key step in this pathway is the interfacial PCET reaction between Y356 and Y731. Simulations suggest that the water-mediated mechanism is unfavorable, while the direct PCET mechanism becomes feasible when Y731 flips towards the interface.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Benjamin J. G. Rousseau, Alexander V. Soudackov, Robert R. Tuttle, Melissa M. Reynolds, Richard G. Finke, Sharon Hammes-Schiffer
Summary: The metal-organic framework Cu-1,3,5-tris[1H-1,2,3-triazol-5-yl]benzene can catalyze the generation of nitric oxide (NO) and glutathione disulfide (GSSG) from S-nitrosoglutathione (GSNO) in aqueous solution. Through experimental and theoretical studies, a catalytic mechanism involving Cu(I) intermediate and sulfur coordination of GSNO was proposed. The inhibition of reactivity at high pH values was explained by the deprotonation of a triazole linker, leading to decreased structural stability of the Cu(I) intermediate. These mechanistic insights are potentially applicable to other MOF catalysts for NO generation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Jahan M. Dawlaty, Sevan Menachekanian, Matthew J. Voegtle, Robert E. Warburton, Sharon Hammes-Schiffer
Summary: Understanding the breaking and formation of Lewis bonds at an electrified interface provides insights into electrocatalysis and electroadsorption. This study demonstrates the stability and reversibility of a Lewis bond on an electrode surface under different electrode potentials. The effects of intramolecular polarization and ionic structures near the electrode play a crucial role in the cleavage of the Lewis bond at negative potentials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Phillips Hutchison, Corey J. Kaminsky, Yogesh Surendranath, Sharon Hammes-Schiffer
Summary: Surface immobilized catalysts are highly promising for energy conversion reactions, and understanding their mechanistic principles is crucial for rational design. This study investigates the behavior of CoTPP on a graphitic surface using density functional theory calculations. The results reveal that the adsorbed molecule undergoes concerted proton-coupled electron transfer, forming a cobalt hydride and avoiding redox reactions. These findings have important implications for electrocatalysis and surface immobilized catalysts.
ACS CENTRAL SCIENCE
(2023)
Editorial Material
Chemistry, Multidisciplinary
Sharon Hammes-Schiffer
Article
Chemistry, Multidisciplinary
Kai Cui, Alexander V. Soudackov, Matthew C. Kessinger, Jeremiah Xu, Gerald J. Meyer, Sharon Hammes-Schiffer
Summary: The pH dependence of proton-coupled electron transfer (PCET) reactions was studied using a multichannel kinetic model. This model showed that a weak pH dependence can arise from competition among different PCET channels involving various forms of redox species. The model was used to explain the weak pH dependence observed in an electrochemical PCET reaction. The study highlights the importance of considering multiple competing channels in PCET processes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Inorganic & Nuclear
Xiaofan Jia, Kai Cui, Jose L. Alvarez-Hernandez, Carrie L. Donley, Albert Gang, Sharon Hammes-Schiffer, Nilay Hazari, Sungho Jeon, James M. Mayer, Hannah S. Nedzbala, Bo Shang, Eric A. Stach, Eleanor Stewart-Jones, Hailiang Wang, Alexa Williams
Summary: Three molecular Re hydrides with silatrane functional groups were synthesized for attachment on metal oxide surfaces. These complexes demonstrated similar electronic properties to a control compound and acted as electrocatalysts for CO2 reduction in solution. However, when immobilized on surfaces, the hydride ligand was lost and the complexes degraded. This work exemplifies the challenges of attaching molecular hydride complexes to metal oxide surfaces.
Article
Chemistry, Physical
Ruozhu Feng, Ying Chen, Xin Zhang, Benjamin J. G. Rousseau, Peiyuan Gao, Ping Chen, Sebastian T. Mergelsberg, Lirong Zhong, Aaron Hollas, Yangang Liang, Vijayakumar Murugesan, Qian Huang, Eric Walter, Sharon Hammes-Schiffer, Yuyan Shao, Wei Wang
Summary: Redox flow batteries with strategically designed proton regulators demonstrate improved kinetics and performance, enhancing rate capability, capacity, and cycling. The addition of b-cyclodextrin organic additive in fluorenone-based flow batteries allows for increased alcohol oxidation rates. This study provides a new avenue for enhancing the kinetics of aqueous organic flow batteries by modulating the reaction pathway with a homogeneous catalyst.
Article
Chemistry, Multidisciplinary
Kai Cui, Alexander V. Soudackov, Matthew C. Kessinger, Jeremiah Xu, Gerald J. Meyer, Sharon Hammes-Schiffer
Summary: The pH dependence of proton-coupled electron transfer (PCET) reactions can be explained by a general, multichannel kinetic model. Multiple sequential and concerted PCET channels, involving different forms of redox species, contribute to a weak pH dependence of PCET apparent rate constants. This model has been used to understand the weak pH dependence observed in an electrochemical PCET reaction involving a ruthenium-based water oxidation catalyst.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Computer Science, Interdisciplinary Applications
Sharon Hammes-Schiffer
Summary: This Perspective provides a summary of modeling strategies that can be combined to address the challenges in proton-coupled electron transfer reactions. The coupling of electron and proton transfer is critical for understanding chemical and biological processes in complex environments. Various computational methods, including analytical theories, quantum chemistry, molecular dynamics, and kinetic modeling, are essential for a comprehensive understanding of such reactions.
NATURE COMPUTATIONAL SCIENCE
(2023)