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Poths P, Zandkarimi B, Alexandrova AN, Jimenez-Izal E. Pt:Ge ratio as a lever of activity and selectivity control of supported PtGe clusters in thermal dehydrogenation. ChemCatChem 2023. [DOI: 10.1002/cctc.202201533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Poths P, Li G, Masubuchi T, Morgan HWT, Zhang Z, Alexandrova AN, Anderson SL. Got Coke? Self-Limiting Poisoning Makes an Ultra Stable and Selective Sub-Nano Cluster Catalyst. ACS Catal 2023. [DOI: 10.1021/acscatal.2c05634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Dickerson CE, Chang C, Guo H, Alexandrova AN. Fully Saturated Hydrocarbons as Hosts of Optical Cycling Centers. J Phys Chem A 2022; 126:9644-9650. [PMID: 36519723 DOI: 10.1021/acs.jpca.2c06647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Designing closed, laser-induced optical cycling transitions in trapped atoms or molecules is useful for quantum information processing, precision measurement, and quantum sensing. Larger molecules that feature such closed transitions are particularly desirable, as the increased degrees of freedom present new structures for optical control and enhanced measurements. The search for molecules with robust optical cycling centers is a challenge which requires design principles beyond trial-and-error. Two such principles are proposed for the particular M-O-R framework, where M is an alkaline earth metal radical, and R is a ligand: (1) Large, saturated hydrocarbons can serve as ligands, R, due to a substantial HOMO-LUMO gap that encloses the cycling transition, so long as the R group is rigid. (2) Electron-withdrawing groups, via induction, can enhance Franck-Condon factors (FCFs) of the optical cycling transition, as long as they do not disturb the locally linear structure in the M-O-R motif. With these tools in mind, larger molecules can be trapped and used as optical cycling centers, sometimes with higher FCFs than smaller molecules.
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Poths P, Hong Z, Li G, Anderson SL, Alexandrova AN. "Magic" Sinter-Resistant Cluster Sizes of Pt n Supported on Alumina. J Phys Chem Lett 2022; 13:11044-11050. [PMID: 36413781 DOI: 10.1021/acs.jpclett.2c03114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Subnano cluster catalysts, while highly promising due to unique activity, selectivity, and atom-efficiency, are limited in wider applications, as they are prone to deactivation via sintering. Even size-selection, which was previously shown to reduce sintering of nanoparticles, cannot reduce the sintering of highly fluxional subnano clusters due to their inherent isomeric diversity. Here, we use a combination of theory and experiment to show that Pt clusters on Al2O3 exhibit size-dependent sintering resistance. We furthermore show that Pt4/Al2O3 and Pt7/Al2O3 are "magic" sinter-resistant cluster sizes. Their stability is attributed to the greater degree of bulk-like crystallinity of the dominant isomers. In addition, we identify different spatial signatures characteristic of the sintering of clusters with differing sintering stabilities.
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Lao G, Zhu GZ, Dickerson CE, Augenbraun BL, Alexandrova AN, Caram JR, Hudson ER, Campbell WC. Laser Spectroscopy of Aromatic Molecules with Optical Cycling Centers: Strontium(I) Phenoxides. J Phys Chem Lett 2022; 13:11029-11035. [PMID: 36413655 PMCID: PMC9720742 DOI: 10.1021/acs.jpclett.2c03040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
We report the production and spectroscopic characterization of strontium(I) phenoxide (SrOC6H5 or SrOPh) and variants featuring electron-withdrawing groups designed to suppress vibrational excitation during spontaneous emission from the electronically excited state. Optical cycling closure of these species, which is the decoupling of the vibrational state changes from spontaneous optical decay, is found by dispersed laser-induced fluorescence spectroscopy to be high, in accordance with theoretical predictions. A high-resolution, rotationally resolved laser excitation spectrum is recorded for SrOPh, allowing the estimation of spectroscopic constants and identification of candidate optical cycling transitions for future work. The results confirm the promise of strontium phenoxides for laser cooling and quantum state detection at the single-molecule level.
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Wilson TR, Morgenstern A, Alexandrova AN, Eberhart ME. Bond Bundle Analysis of Ketosteroid Isomerase. J Phys Chem B 2022; 126:9443-9456. [PMID: 36383139 DOI: 10.1021/acs.jpcb.2c03638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bond bundle analysis is used to investigate enzymatic catalysis in the ketosteroid isomerase (KSI) active site. We identify the unique bonding regions in five KSI systems, including those exposed to applied oriented electric fields and those with amino acid mutations, and calculate the precise redistribution of electron density and other regional properties that accompanies either enhancement or inhibition of KSI catalytic activity. We find that catalytic enhancement results from promoting both inter- and intra-molecular electron density redistribution, between bond bundles and bond wedges within the KSI-docked substrate molecule, in the forward direction of the catalyzed reaction. Though the redistribution applies to both types of perturbed systems and is thus suggestive of a general catalytic role, we observe that bond properties (e.g., volume vs energy vs electron count) can respond independently and disproportionately depending on the type of perturbation. We conclude that the resulting catalytic enhancement/inhibition proceeds via different mechanisms, where some bond properties are utilized more by one type of perturbation than the other. Additionally, we find that the correlations between bond wedge properties and catalyzed reaction barrier energies are additive to predict those of bond bundles and atomic basins, providing a rigorous grounding for connecting changes in local charge density to resulting shifts in reaction barrier energy.
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Munarriz J, Zhang Z, Sautet P, Alexandrova AN. Graphite-Supported Pt n Cluster Electrocatalysts: Major Change of Active Sites as a Function of the Applied Potential. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Morgan HWT, Alexandrova AN. Electron Counting and High-Pressure Phase Transformations in Metal Hexaborides. Inorg Chem 2022; 61:18701-18709. [DOI: 10.1021/acs.inorgchem.2c03190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Zhang Z, Wei Z, Sautet P, Alexandrova AN. Hydrogen-Induced Restructuring of a Cu(100) Electrode in Electroreduction Conditions. J Am Chem Soc 2022; 144:19284-19293. [PMID: 36227161 DOI: 10.1021/jacs.2c06188] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rearrangement of Cu surfaces under electrochemical conditions is known to play a key role in the surface activation for major electrocatalytic reactions. Despite the extensive experimental insights into such rearrangements, from surface-sensitive spectroscopy and microscopy, the spatial and temporal resolution of these methods is insufficient to provide an atomistic picture of the electrochemical interface. Theoretical characterization has also been challenged by the diversity of restructuring configurations, surface stoichiometry, adsorbate configurations, and the effect of the electrode potential. Here, atomistic insight into the restructuring of the electrochemical interface is gained from first principles. Cu(100) restructuring under varying applied potentials and adsorbate coverages is studied by grand canonical density functional theory and global optimization techniques, as well as ab initio molecular dynamics and mechanistic calculations. We show that electroreduction conditions cause the formation of a shifted-row reconstruction on Cu(100), induced by hydrogen adsorption. The reconstruction is initiated at 1/6 ML H coverage, when the Cu-H bonding sufficiently weakens the Cu-Cu bonds between the top- and sublayer, and further stabilized at 1/3 ML when H adsorbates fill all the created 3-fold hollow sites. The simulated scanning tunneling microscopy (STM) images of the calculated reconstructed interfaces agree with experimental in situ STM. However, compared to the thermodynamic prediction, the onsets of reconstruction events in the experiment occur at more negative applied voltages. This is attributed to kinetic effects in restructuring, which we describe via different statistical models, to produce the potential- and pH-dependent surface stability diagram. This manuscript provides rich atomistic insight into surface restructuring in electroreduction conditions, which is required for the understanding and design of Cu-based materials for electrocatalytic processes. It also offers the methodology to study the problem of in situ electrode reconstruction.
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Barlow JM, Clarke LE, Zhang Z, Bím D, Ripley KM, Zito A, Brushett FR, Alexandrova AN, Yang JY. Molecular design of redox carriers for electrochemical CO 2 capture and concentration. Chem Soc Rev 2022; 51:8415-8433. [PMID: 36128984 DOI: 10.1039/d2cs00367h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Developing improved methods for CO2 capture and concentration (CCC) is essential to mitigating the impact of our current emissions and can lead to carbon net negative technologies. Electrochemical approaches for CCC can achieve much higher theoretical efficiencies compared to the thermal methods that have been more commonly pursued. The use of redox carriers, or molecular species that can bind and release CO2 depending on their oxidation state, is an increasingly popular approach as carrier properties can be tailored for different applications. The key requirements for stable and efficient redox carriers are discussed in the context of chemical scaling relationships and operational conditions. Computational and experimental approaches towards developing redox carriers with optimal properties are also described.
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Mitra D, Lasner ZD, Zhu GZ, Dickerson CE, Augenbraun BL, Bailey AD, Alexandrova AN, Campbell WC, Caram JR, Hudson ER, Doyle JM. Pathway toward Optical Cycling and Laser Cooling of Functionalized Arenes. J Phys Chem Lett 2022; 13:7029-7035. [PMID: 35900113 DOI: 10.1021/acs.jpclett.2c01430] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Rapid and repeated photon cycling has enabled precision metrology and the development of quantum information systems using atoms and simple molecules. Extending optical cycling to structurally complex molecules would provide new capabilities in these areas, as well as in ultracold chemistry. Increased molecular complexity, however, makes realizing closed optical transitions more difficult. Building on already established strong optical cycling of diatomic, linear triatomic, and symmetric top molecules, recent work has pointed the way to cycling of larger molecules, including phenoxides. The paradigm for these systems is an optical cycling center bonded to a molecular ligand. Theory has suggested that cycling may be extended to even larger ligands, like naphthalene, pyrene, and coronene. Herein, we study optical excitation and fluorescent vibrational branching of CaO-[Formula: see text], SrO-[Formula: see text], and CaO-[Formula: see text] and find only weak decay to excited vibrational states, indicating a promising path to full quantum control and laser cooling of large arene-based molecules.
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Zhu GZ, Mitra D, Augenbraun BL, Dickerson CE, Frim MJ, Lao G, Lasner ZD, Alexandrova AN, Campbell WC, Caram JR, Doyle JM, Hudson ER. Functionalizing aromatic compounds with optical cycling centres. Nat Chem 2022; 14:995-999. [PMID: 35879444 DOI: 10.1038/s41557-022-00998-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 06/14/2022] [Indexed: 12/13/2022]
Abstract
Molecular design principles provide guidelines for augmenting a molecule with a smaller group of atoms to realize a desired property or function. We demonstrate that these concepts can be used to create an optical cycling centre, the Ca(I)-O unit, that can be attached to a number of aromatic ligands, enabling the scattering of many photons from the resulting molecules without changing the molecular vibrational state. Such capability plays a central role in quantum state preparation and measurement, as well as laser cooling and trapping, and is therefore a prerequisite for many quantum science and technology applications. We provide further molecular design principles that indicate the ability to optimize and expand this work to an even broader class of molecules. This represents a great step towards a quantum functional group, which may serve as a generic qubit moiety that can be attached to a wide range of molecular structures and surfaces.
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Xian W, Hennefarth MR, Lee MW, Do T, Lee EY, Alexandrova AN, Wong GCL. Histidine-Mediated Ion Specific Effects Enable Salt Tolerance of a Pore-Forming Marine Antimicrobial Peptide. Angew Chem Int Ed Engl 2022; 61:e202108501. [PMID: 35352449 DOI: 10.1002/anie.202108501] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Indexed: 12/19/2022]
Abstract
Antimicrobial peptides (AMPs) preferentially permeate prokaryotic membranes via electrostatic binding and membrane remodeling. Such action is drastically suppressed by high salt due to increased electrostatic screening, thus it is puzzling how marine AMPs can possibly work. We examine as a model system, piscidin-1, a histidine-rich marine AMP, and show that ion-histidine interactions play unanticipated roles in membrane remodeling at high salt: Histidines can simultaneously hydrogen-bond to a phosphate and coordinate with an alkali metal ion to neutralize phosphate charge, thereby facilitating multidentate bonds to lipid headgroups in order to generate saddle-splay curvature, a prerequisite to pore formation. A comparison among Na+ , K+ , and Cs+ indicates that histidine-mediated salt tolerance is ion specific. We conclude that histidine plays a unique role in enabling protein/peptide-membrane interactions that occur in marine or other high-salt environment.
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Zhang Z, Zandkarimi B, Munarriz J, Dickerson CE, Alexandrova AN. Fluxionality of Subnano Clusters Reshapes the Activity Volcano of Electrocatalysis. ChemCatChem 2022. [DOI: 10.1002/cctc.202200345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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40
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Poths P, Alexandrova AN. Theoretical Perspective on Operando Spectroscopy of Fluxional Nanocatalysts. J Phys Chem Lett 2022; 13:4321-4334. [PMID: 35536346 DOI: 10.1021/acs.jpclett.2c00628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Improvements in operando spectroscopy have enabled the catalysis community to investigate the dynamic nature of catalysts under operating conditions with increasing detail. Still, the highly dynamic nature of some catalysts, such as fluxional supported subnano clusters, presents a formidable challenge even for the most state-of-the-art techniques. The reason is that such fluxional catalytic interfaces contain a variety of thermally accessible states. Operando spectroscopies used in catalysis generally fall into two categories: ensemble-based techniques, which provide spectra containing the signals of the entire ensemble of states of the catalyst and are not necessarily dominated by the most active species, and localized techniques, which provide atomistic-level information about the dynamics of active sites in a very small area, which might not include the most active species. Combining many different kinds of techniques can provide detailed insight; however, we propose that effective utilization of specific computational techniques and approaches within the fluxionality paradigm can fill the gap and enable atomistic characterization of the most relevant catalytic sites.
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Xian W, Hennefarth MR, Lee MW, Do T, Lee EY, Alexandrova AN, Wong GCL. Histidine‐Mediated Ion Specific Effects Enable Salt Tolerance of a Pore‐Forming Marine Antimicrobial Peptide. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202108501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bím D, Navrátil M, Gutten O, Konvalinka J, Kutil Z, Culka M, Navrátil V, Alexandrova AN, Bařinka C, Rulíšek L. Predicting Effects of Site-Directed Mutagenesis on Enzyme Kinetics by QM/MM and QM Calculations: A Case of Glutamate Carboxypeptidase II. J Phys Chem B 2022; 126:132-143. [PMID: 34978450 DOI: 10.1021/acs.jpcb.1c09240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Quantum and molecular mechanics (QM/MM) and QM-only (cluster model) modeling techniques represent the two workhorses in mechanistic understanding of enzyme catalysis. One of the stringent tests for QM/MM and/or QM approaches is to provide quantitative answers to real-world biochemical questions, such as the effect of single-point mutations on enzyme kinetics. This translates into predicting the relative activation energies to 1-2 kcal·mol-1 accuracy; such predictions can be used for the rational design of novel enzyme variants with desired/improved characteristics. Herein, we employ glutamate carboxypeptidase II (GCPII), a dizinc metallopeptidase, also known as the prostate specific membrane antigen, as a model system. The structure and activity of this major cancer antigen have been thoroughly studied, both experimentally and computationally, which makes it an ideal model system for method development. Its reaction mechanism is quite well understood: the reaction coordinate comprises a "tetrahedral intermediate" and two transition states and experimental activation Gibbs free energy of ∼17.5 kcal·mol-1 can be inferred for the known kcat ≈ 1 s-1. We correlate experimental kinetic data (including the E424H variant, newly characterized in this work) for various GCPII mutants (kcat = 8.6 × 10-5 s-1 to 2.7 s-1) with the energy profiles calculated by QM/MM and QM-only (cluster model) approaches. We show that the near-quantitative agreement between the experimental values and the calculated activation energies (ΔH⧧) can be obtained and recommend the combination of the two protocols: QM/MM optimized structures and cluster model (QM) energetics. The trend in relative activation energies is mostly independent of the QM method (DFT functional) used. Last but not least, a satisfactory correlation between experimental and theoretical data allows us to provide qualitative and fairly simple explanations of the observed kinetic effects which are thus based on a rigorous footing.
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Hassan IS, Fuller JT, Dippon VN, Ta AN, Danneman MW, McNaughton BR, Alexandrova AN, Rovis T. Tuning Through-Space Interactions via the Secondary Coordination Sphere of an Artificial Metalloenzyme Leads to Enhanced Rh(III)-Catalysis. Chem Sci 2022; 13:9220-9224. [PMID: 36093000 PMCID: PMC9384688 DOI: 10.1039/d2sc03674f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/28/2022] [Indexed: 11/21/2022] Open
Abstract
We report computationally-guided protein engineering of monomeric streptavidin Rh(iii) artificial metalloenzyme to enhance catalysis of the enantioselective coupling of acrylamide hydroxamate esters and styrenes. Increased TON correlates with calculated distances between the Rh(iii) metal and surrounding residues, underscoring an artificial metalloenzyme's propensity for additional control in metal-catalyzed transformations by through-space interactions. We report computationally-guided protein engineering of monomeric streptavidin Rh(iii) artificial metalloenzyme to enhance catalysis of the enantioselective coupling of acrylamide hydroxamate esters and styrenes.![]()
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Lavroff RH, Morgan HWT, Zhang Z, Poths P, Alexandrova AN. Ensemble representation of catalytic interfaces: soloists, orchestras, and everything in-between. Chem Sci 2022; 13:8003-8016. [PMID: 35919426 PMCID: PMC9278157 DOI: 10.1039/d2sc01367c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022] Open
Abstract
Catalytic systems are complex and dynamic, exploring vast chemical spaces on multiple timescales. In this perspective, we discuss the dynamic behavior of fluxional, heterogeneous thermal and electrocatalysts and the ensembles of many isomers which govern their behavior. We develop a new paradigm in catalysis theory in which highly fluxional systems, namely sub-nano clusters, isomerize on a much shorter timescale than that of the catalyzed reaction, so macroscopic properties arise from the thermal ensemble of isomers, not just the ground state. Accurate chemical predictions can only be reached through a many-structure picture of the catalyst, and we explain the breakdown of conventional methods such as linear scaling relations and size-selected prevention of sintering. We capitalize on the forward-looking discussion of the means of controlling the size of these dynamic ensembles. This control, such that the most effective or selective isomers can dominate the system, is essential for the fluxional catalyst to be practicable, and their targeted synthesis to be possible. It will also provide a fundamental lever of catalyst design. Finally, we discuss computational tools and experimental methods for probing ensembles and the role of specific isomers. We hope that catalyst optimization using chemically informed descriptors of ensemble nature and size will become a new norm in the field of catalysis and have broad impacts in sustainable energy, efficient chemical production, and more. Catalytic systems are complex and dynamic, exploring vast chemical spaces on multiple timescales.![]()
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Guo H, Poths P, Sautet P, Alexandrova AN. Oxidation Dynamics of Supported Catalytic Cu Clusters: Coupling to Fluxionality. ACS Catal 2021. [DOI: 10.1021/acscatal.1c04100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wilson TR, Alexandrova AN, Eberhart ME. Electron Density Geometry and the Quantum Theory of Atoms in Molecules. J Phys Chem A 2021; 125:10622-10631. [PMID: 34905923 DOI: 10.1021/acs.jpca.1c09359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel form of charge density analysis, that of isosurface curvature redistribution, is formulated and applied to the toy problem of carbonyl oxygen activation in formaldehyde. The isosurface representation of the electron charge density allows us to incorporate the rigorous geometric constraints of closed surfaces toward the analysis and chemical interpretation of the charge density response to perturbations. Visual inspection of 2D isosurface motion resulting from applied external electric fields reveals how the isosurface curvature flows within and between atoms and that a molecule can be uniquely and completely partitioned into chemically significant regions of positive and negative curvatures. These concepts reveal that carbonyl oxygen activation proceeds primarily through curvature and charge redistribution within rather than between Bader atoms. Using gradient bundle analysis─the partitioning of formaldehyde into infinitesimal volume elements bounded by QTAIM zero-flux surfaces─the observations from visual isosurface inspection are verified. The results of the formaldehyde carbonyl analysis are then shown to be transferable to the substrate carbonyl in the ketosteroid isomerase enzyme, laying the groundwork for extending this approach to the problems of enzymatic catalysis.
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Vargas S, Hennefarth MR, Liu Z, Alexandrova AN. Correction to Machine Learning to Predict Diels-Alder Reaction Barriers from the Reactant State Electron Density. J Chem Theory Comput 2021; 18:595. [PMID: 34910483 DOI: 10.1021/acs.jctc.1c01134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Deng J, Lin S, Fuller JT, Zandkarimi B, Chen HM, Alexandrova AN, Liu C. Electrocatalytic Methane Functionalization with d
0
Early Transition Metals Under Ambient Conditions. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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49
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Deng J, Lin SC, Fuller JT, Zandkarimi B, Chen HM, Alexandrova AN, Liu C. Electrocatalytic Methane Functionalization with d 0 Early Transition Metals Under Ambient Conditions. Angew Chem Int Ed Engl 2021; 60:26630-26638. [PMID: 34606678 DOI: 10.1002/anie.202107720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Indexed: 11/09/2022]
Abstract
The undesirable loss of methane (CH4 ) at remote locations welcomes approaches that ambiently functionalize CH4 on-site without intense infrastructure investment. Recently, we found that electrochemical oxidation of vanadium(V)-oxo with bisulfate ligand leads to CH4 activation at ambient conditions. The key question is whether such an observation is a one-off coincidence or a general strategy for electrocatalyst design. Here, a general scheme of electrocatalytic CH4 activation with d0 early transition metals is established. The pre-catalysts' molecular structure, electrocatalytic kinetics, and mechanism were detailed for titanium (IV), vanadium (V), and chromium (VI) species as model systems. After a turnover-limiting one-electron electrochemical oxidation, the yielded ligand-centered cation radicals activate CH4 with low activation energy and high selectivity. The reactivities are universal among early transition metals from Period 4 to 6, and the reactivities trend for different early transition metals correlate with their d orbital energies across periodic table. Our results offer new chemical insights towards developing advanced ambient electrocatalysts of natural gas.
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Lavroff RH, Pennington DL, Hua AS, Li BY, Williams JA, Alexandrova AN. Recent Innovations in Solid-State and Molecular Qubits for Quantum Information Applications. J Phys Chem A 2021; 125:9567-9570. [PMID: 34758615 DOI: 10.1021/acs.jpca.1c08677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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