1
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Lätsch L, Guda SA, Romankov V, Wartmann C, Neudörfl JM, Dreiser J, Berkessel A, Guda AA, Copéret C. Tracking Coordination Environment and Reaction Intermediates in Homogeneous and Heterogeneous Epoxidation Catalysts via Ti L 2,3-Edge Near-Edge X-ray Absorption Fine Structures. J Am Chem Soc 2024; 146:7456-7466. [PMID: 38447178 DOI: 10.1021/jacs.3c12831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Ti-based molecules and materials are ubiquitous and play a major role in both homogeneous and heterogeneous catalytic processes. Understanding the electronic structures of their active sites (oxidation state, local symmetry, and ligand environment) is key to developing molecular-level structure-property relationships. In that context, X-ray absorption spectroscopy (XAS) offers a unique combination of elemental selectivity and sensitivity to local symmetry. Commonly, for early transition metals such as Ti, K-edge XAS is applied for in situ characterization and subsequent structural analysis with high sensitivity toward tetrahedral species. Ti L2,3-edge spectroscopy is in principle complementary and offers specific opportunities to interrogate the electronic structure of five-and six-coordinated species. It is, however, much more rarely implemented because the use of soft X-rays implies ultrahigh vacuum conditions. Furthermore, the interpretation of the data can be challenging. Here, we show how Ti L2,3-edge spectroscopy can help to obtain unique information about both homogeneous and heterogeneous epoxidation catalysts and develop a molecular-level relationship between spectroscopic signatures and electronic structures. Toward this goal, we first establish a spectral library of molecular Ti reference compounds, comprising various coordination environments with mono- and dimeric Ti species having O, N, and Cl ligands. We next implemented a computational methodology based on multiplet ligand field theory and maximally localized Wannier orbitals benchmarked on our library to understand Ti L2,3-edge spectroscopic signatures. We finally used this approach to track and predict the spectra of catalytically relevant intermediates, focusing on Ti-based olefin epoxidation catalysts.
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Affiliation(s)
- Lukas Lätsch
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 2, CH 8093Zurich, Switzerland
| | - Sergey A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178324, 344090Rostov-on-Don, Russia
| | - Vladyslav Romankov
- Swiss Light Source, Paul Scherrer Institut, CH-5232Villigen, Switzerland
| | - Christina Wartmann
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Jörg-M Neudörfl
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Jan Dreiser
- Swiss Light Source, Paul Scherrer Institut, CH-5232Villigen, Switzerland
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Alexander A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178324, 344090Rostov-on-Don, Russia
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 2, CH 8093Zurich, Switzerland
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2
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De Jesús Báez LR, Rosas AS, Mahale P, Mallouk TE. Chelation-Based Route to Aluminum-Free Layered Transition Metal Carbides (MXenes). ACS OMEGA 2023; 8:41969-41976. [PMID: 37970010 PMCID: PMC10633885 DOI: 10.1021/acsomega.3c07442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/05/2023] [Accepted: 10/10/2023] [Indexed: 11/17/2023]
Abstract
MXenes are of much interest because of their electrochemical, electronic, and surface chemical properties that arise from their structure and stoichiometry. The integrity and the nature of the terminal groups on the basal planes of MXene sheets depend strongly on the method used to etch the parent MAX (M = transition metal, A = Al, X = C, N, B) compound. Aluminum removal typically involves a high concentration of aqueous HF, HCl/LiF mixtures, or fluoride solutions of strong acids. HF etching is problematic because it leaves insoluble AlF3 in the product, degrades the crystallinity of the nanosheets, and results in the termination of the basal planes with F, O, or OH groups. Here, we demonstrate the use of HF at a low concentration in tandem with a chelating agent, N,N'-dihydroxyoctanediamide (suberohydroxamic acid), to selectively etch the archetypical MAX compound Ti3AlC2 at room temperature. X-ray absorption spectroscopy (XAS) of the etched materials shows that the carbide nature of bonding in the parent MAX structure is retained in the MXene layers. The stability of the MXene in aqueous suspensions is also significantly improved relative to MXene products made by etching in concentrated HF solutions.
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Affiliation(s)
- Luis R. De Jesús Báez
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department
of Chemistry, University at Buffalo, Buffalo, New York 14260, United States
| | - Alyssa S. Rosas
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Pratibha Mahale
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Thomas E. Mallouk
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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3
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Du J, Huang Y, Huang Z, Wu G, Wu B, Han X, Chen C, Zheng X, Cui P, Wu Y, Jiang J, Hong X. Reversing the Catalytic Selectivity of Single-Atom Ru via Support Amorphization. JACS AU 2022; 2:1078-1083. [PMID: 35647593 PMCID: PMC9131367 DOI: 10.1021/jacsau.2c00192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/04/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Supported single-atom catalysts (SACs), with the extremely homogenized active sites could achieve high hydrogenation selectivity toward one of the functional groups coexisting in the reactant molecule. However, as to the target group, the control of selective recognition and activation by SACs still remains a challenge. Herein, the phase engineering of the support is adopted to control the chemo-recognition behavior of SACs in selective hydrogenation. Single-atom Ru on amorphous porous ultrathin TiO2 nanosheets (Ru1/a-TiO2) is constructed, in which Ru is more positively charged than that in the crystalline counterpart (Ru1/c-TiO2). Moreover, in the nitro/vinyl selective hydrogenation process, Ru1/a-TiO2 shows superior nitro selectivity, opposite to the vinyl selectivity of Ru1/c-TiO2. Density functional theory calculations for single-atom Ru of different charge states show that the reactant adsorption configuration could be inverted in the amorphous TiO2, accounting for the chemo-recognition behavior controlled by the phase of support.
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Affiliation(s)
- Junyi Du
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
- Division
of Advanced Materials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Yan Huang
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Zixiang Huang
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
- National
Synchrotron Radiation Laboratory (NSRL), University of Science and Technology of China, Hefei 230029, P. R. China
| | - Geng Wu
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Bei Wu
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xiao Han
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Cai Chen
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xusheng Zheng
- National
Synchrotron Radiation Laboratory (NSRL), University of Science and Technology of China, Hefei 230029, P. R. China
| | - Peixin Cui
- Key
Laboratory of Soil Environment and Pollution Remediation, Institute
of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P. R. China
| | - Yuen Wu
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Jun Jiang
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xun Hong
- Center
of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
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4
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Chiu CC, Ho SZ, Lee JM, Shao YC, Shen Y, Liu YC, Chang YW, Zheng YZ, Huang R, Chang CF, Kuo CY, Duan CG, Huang SW, Yang JC, Chuang YD. Presence of Delocalized Ti 3d Electrons in Ultrathin Single-Crystal SrTiO 3. NANO LETTERS 2022; 22:1580-1586. [PMID: 35073104 DOI: 10.1021/acs.nanolett.1c04434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Strontium titanate (STO), with a wide spectrum of emergent properties such as ferroelectricity and superconductivity, has received significant attention in the community of strongly correlated materials. In the strain-free STO film grown on the SrRuO3 buffer layer, the existing polar nanoregions can facilitate room-temperature ferroelectricity when the STO film thickness approaches 10 nm. Here we show that around this thickness scale, the freestanding STO films without the influence of a substrate show the tetragonal structure at room temperature, contrasting with the cubic structure seen in bulk form. The spectroscopic measurements reveal the modified Ti-O orbital hybridization that causes the Ti ion to deviate from its nominal 4+ valency (3d0 configuration) with excess delocalized 3d electrons. Additionally, the Ti ion in TiO6 octahedron exhibits an off-center displacement. The inherent symmetry lowering in ultrathin freestanding films offers an alternative way to achieve tunable electronic structures that are of paramount importance for future technological applications.
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Affiliation(s)
- Chun-Chien Chiu
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Sheng-Zhu Ho
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Jenn-Min Lee
- MAX IV Laboratory, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - Yu-Cheng Shao
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yang Shen
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Yu-Chen Liu
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Yao-Wen Chang
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Yun-Zhe Zheng
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Rong Huang
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Chun-Fu Chang
- Max-Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | - Chang-Yang Kuo
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Chun-Gang Duan
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Shih-Wen Huang
- MAX IV Laboratory, Lund University, P.O. Box 118, 221 00 Lund, Sweden
- Swiss Light Source, Paul Scherrer Institut, CH5232 Villigen PSI, Switzerland
| | - Jan-Chi Yang
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 70101, Taiwan
| | - Yi-De Chuang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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5
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Kunnus K, Guo M, Biasin E, Larsen CB, Titus CJ, Lee SJ, Nordlund D, Cordones AA, Uhlig J, Gaffney KJ. Quantifying the Steric Effect on Metal-Ligand Bonding in Fe Carbene Photosensitizers with Fe 2p3d Resonant Inelastic X-ray Scattering. Inorg Chem 2022; 61:1961-1972. [PMID: 35029978 DOI: 10.1021/acs.inorgchem.1c03124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the electronic structure and chemical bonding of transition metal complexes is important for improving the function of molecular photosensitizers and catalysts. We have utilized X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) at the Fe L3 edge to investigate the electronic structure of two Fe N-heterocyclic carbene complexes with similar chemical structures but different steric effects and contrasting excited-state dynamics: [Fe(bmip)2]2+ and [Fe(btbip)2]2+, bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)pyridine and btbip = 2,6-bis(3-tert-butyl-imidazole-1-ylidene)pyridine. In combination with charge transfer multiplet and ab initio calculations, we quantified how changes in Fe-carbene bond length due to steric effects modify the metal-ligand bonding, including σ/π donation and π back-donation. We find that σ donation is significantly stronger in [Fe(bmip)2]2+, whereas the π back-donation is similar in both complexes. The resulting stronger ligand field and nephelauxetic effect in [Fe(bmip)2]2+ lead to approximately 1 eV destabilization of the quintet metal-centered 5T2g excited state compared to [Fe(btbip)2]2+, providing an explanation for the absence of a photoinduced 5T2g population and a longer metal-to-ligand charge-transfer excited-state lifetime in [Fe(bmip)2]2+. This work demonstrates how combined modeling of XAS and RIXS spectra can be utilized to understand the electronic structure of transition metal complexes governed by correlated electrons and donation/back-donation interactions.
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Affiliation(s)
- Kristjan Kunnus
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States.,Institute of Physics, University of Tartu, W. Ostwaldi 1, Tartu EE-50411, Estonia
| | - Meiyuan Guo
- Department of Chemistry, Lund University, Lund SE-22100, Sweden
| | - Elisa Biasin
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Christopher B Larsen
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Charles J Titus
- Department of Physics, Stanford University, Stanford, California 94305, United States
| | - Sang Jun Lee
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Dennis Nordlund
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Amy A Cordones
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Jens Uhlig
- Department of Chemistry, Lund University, Lund SE-22100, Sweden
| | - Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
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6
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Whittle TA, Lu T, Blanchard P, R. Hester J, Gu Q, Liu Y, Schmid S. Synthesis, structure and dielectric properties of the Sr 3Ti 1−xZr xNb 4O 15, (0 ≤ x ≤ 1), series of tungsten bronze type compounds. CrystEngComm 2020. [DOI: 10.1039/d0ce00425a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High temperature phase transitions from Pna21 to P4/mbm are observed for all compositions, and transition temperatures increase with Zr content.
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Affiliation(s)
| | - Teng Lu
- Research School of Chemistry
- Australian National University
- Canberra
- Australia
| | | | - James R. Hester
- Australian Centre for Neutron Scattering
- Australian Nuclear Science and Technology Organisation
- Kirrawee DC
- Australia
| | - Qinfen Gu
- Australian Synchrotron
- Australian Nuclear Science and Technology Organisation
- Clayton
- Australia
| | - Yun Liu
- Research School of Chemistry
- Australian National University
- Canberra
- Australia
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7
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Wu M, Xin HL, Wang JO, Li XJ, Yuan XB, Zeng H, Zheng JC, Wang HQ. Investigation of the multiplet features of SrTiO 3 in X-ray absorption spectra based on configuration interaction calculations. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:777-784. [PMID: 29714188 DOI: 10.1107/s160057751800423x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
Synchrotron-based L2,3-edge absorption spectra show strong sensitivities to the local electronic structure and chemical environment. However, detailed physical information cannot be extracted easily without computational aids. Here, using the experimental Ti L2,3-edges absorption spectrum of SrTiO3 as a fingerprint and considering full multiplet effects, calculations yield different energy parameters characterizing local ground state properties. The peak splitting and intensity ratios of the L3 and L2 set of peaks are carefully analyzed quantitatively, giving rise to a small hybridization energy around 1.2 eV, and the different hybridization energy values reported in the literature are further addressed. Finally, absorption spectra with different linearly polarized photons under various tetragonal crystal fields are investigated, revealing a non-linear orbital-lattice interaction, and a theoretical guidance for material engineering of SrTiO3-based thin films and heterostructures is offered. Detailed analysis of spectrum shifts with different tetragonal crystal fields suggests that the eg crystal field splitting is a necessary parameter for a thorough analysis of the spectra, even though it is not relevant for the ground state properties.
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Affiliation(s)
- M Wu
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - Houlin L Xin
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - J O Wang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - X J Li
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - X B Yuan
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - H Zeng
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - J C Zheng
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - H Q Wang
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
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8
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Hunault MOJY, Harada Y, Miyawaki J, Wang J, Meijerink A, de Groot FMF, van Schooneveld MM. Direct Observation of Cr 3+ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry. J Phys Chem A 2018; 122:4399-4413. [PMID: 29660293 PMCID: PMC6023264 DOI: 10.1021/acs.jpca.8b00984] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
![]()
The
role of transition metals in chemical reactions is often derived
from probing the metal 3d states. However, the relation between metal
site geometry and 3d electronic states, arising from multielectronic
effects, makes the spectral data interpretation and modeling of these
optical excited states a challenge. Here we show, using the well-known
case of red ruby, that unique insights into the density of transition
metal 3d excited states can be gained with 2p3d resonant inelastic
X-ray scattering (RIXS). We compare the experimental determination
of the 3d excited states of Cr3+ impurities in Al2O3 with 190 meV resolution 2p3d RIXS to optical absorption
spectroscopy and to simulations. Using the crystal field multiplet
theory, we calculate jointly for the first time the Cr3+ multielectronic states, RIXS, and optical spectra based on a unique
set of parameters. We demonstrate that (i) anisotropic 3d multielectronic
interactions causes different scaling of Slater integrals, and (ii)
a previously not observed doublet excited state exists around 3.35
eV. These results allow to discuss the influence of interferences
in the RIXS intermediate state, of core–hole lifetime broadenings,
and of selection rules on the RIXS intensities. Finally, our results
demonstrate that using an intermediate excitation energy between L3 and L2 edges allows measurement of the density
of 3d excited states as a fingerprint of the metal local structure.
This opens up a new direction to pump-before-destroy investigations
of transition metal complex structures and reaction mechanisms.
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Affiliation(s)
- Myrtille O J Y Hunault
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherlands
| | - Yoshihisa Harada
- Institute for Solid State Physics , University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
| | - Jun Miyawaki
- Institute for Solid State Physics , University of Tokyo , Kashiwa , Chiba 277-8581 , Japan
| | - Jian Wang
- Canadian Light Source Inc. , Saskatoon , Saskatchewan S7N 2V3 Canada
| | - Andries Meijerink
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherland
| | - Frank M F de Groot
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherlands
| | - Matti M van Schooneveld
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science , Utrecht University , 3584CG Utrecht , The Netherlands
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9
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Wu M, Zheng JC, Wang HQ. Investigation of the multiplet structures and crystal field effects of a TiO6 3d
1 cluster based on configuration interaction calculations. J Appl Crystallogr 2017. [DOI: 10.1107/s160057671700334x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Configuration interaction cluster calculation can effectively reproduce the experimentally measured Ti L
23-edge absorption spectrum for the TiO6 cluster LaTiO3. A further investigation of the hybridization strength and charge-transfer energy effects on the multiplet structures suggests that LaTiO3 should be classified as an intermediate state between the charge-transfer and Mott–Hubbard regimes. Detailed temperature-dependent simulations of absorption spectra support the lifting of Ti t
2g
orbital degeneracy and crystal field splitting. The spin–orbit coupling scenario is ruled out, even though 3d spin–orbit coupling can reproduce the experimental spectrum without including temperature. A combined polarization- and crystal-field-splitting-dependent analysis indicates asymmetric ΔCF–orbital interactions for the TiO6 cluster [Ti3+:3d
1(t
2g
1)], different from the orbital–lattice interactions reported for the NiO6 cluster [Ni3+:3d
7(t
2g
6
eg
1)]. The orbital polarization is defined in terms of the normalized electron occupancies in orbitals with xy and xz(yz) symmetries, and nearly complete orbital polarization (more than 75%) is observed, indicating strongly reduced orbital fluctuations due to the correlation effects. This is consistent with the density of states for titanates based on local density approximation plus dynamical mean-field theory calculations.
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10
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Kunnus K, Josefsson I, Schreck S, Quevedo W, Miedema P, Techert S, de Groot F, Föhlisch A, Odelius M, Wernet P. Quantifying covalent interactions with resonant inelastic soft X-ray scattering: Case study of Ni2+ aqua complex. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.12.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Delgado-Jaime MU, Zhang K, Vura-Weis J, de Groot FMF. CTM4DOC: electronic structure analysis from X-ray spectroscopy. JOURNAL OF SYNCHROTRON RADIATION 2016; 23:1264-71. [PMID: 27577785 PMCID: PMC5006656 DOI: 10.1107/s1600577516012443] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 08/01/2016] [Indexed: 05/29/2023]
Abstract
Two electronic structure descriptions, one based on orbitals and the other based on term symbols, have been implemented in a new Matlab-based program, CTM4DOC. The program includes a graphical user interface that allows the user to explore the dependence of details of electronic structure in transition metal systems, both in the ground and core-hole excited states, on intra-atomic electron-electron, crystal-field and charge-transfer interactions. The program can also track the evolution of electronic structure features as the crystal-field parameters are systematically varied, generating Tanabe-Sugano-type diagrams. Examples on first-row transition metal systems are presented and the implications on the interpretation of X-ray spectra and on the understanding of low-spin, high-spin and mixed-spin systems are discussed.
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Affiliation(s)
- Mario Ulises Delgado-Jaime
- Inorganic Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, The Netherlands
| | - Kaili Zhang
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Josh Vura-Weis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Frank M. F. de Groot
- Inorganic Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, The Netherlands
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12
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Rees JA, Wandzilak A, Maganas D, Wurster NIC, Hugenbruch S, Kowalska JK, Pollock CJ, Lima FA, Finkelstein KD, DeBeer S. Experimental and theoretical correlations between vanadium K-edge X-ray absorption and Kβ emission spectra. J Biol Inorg Chem 2016; 21:793-805. [PMID: 27251139 PMCID: PMC4989026 DOI: 10.1007/s00775-016-1358-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 04/29/2016] [Indexed: 11/28/2022]
Abstract
A series of vanadium compounds was studied by K-edge X-ray absorption (XAS) and K[Formula: see text] X-ray emission spectroscopies (XES). Qualitative trends within the datasets, as well as comparisons between the XAS and XES data, illustrate the information content of both methods. The complementary nature of the chemical insight highlights the success of this dual-technique approach in characterizing both the structural and electronic properties of vanadium sites. In particular, and in contrast to XAS or extended X-ray absorption fine structure (EXAFS), we demonstrate that valence-to-core XES is capable of differentiating between ligating atoms with the same identity but different bonding character. Finally, density functional theory (DFT) and time-dependent DFT calculations enable a more detailed, quantitative interpretation of the data. We also establish correction factors for the computational protocols through calibration to experiment. These hard X-ray methods can probe vanadium ions in any oxidation or spin state, and can readily be applied to sample environments ranging from solid-phase catalysts to biological samples in frozen solution. Thus, the combined XAS and XES approach, coupled with DFT calculations, provides a robust tool for the study of vanadium atoms in bioinorganic chemistry.
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Affiliation(s)
- Julian A Rees
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA, 98195-1700, USA
| | - Aleksandra Wandzilak
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059, Kraków, Poland
| | - Dimitrios Maganas
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Nicole I C Wurster
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Stefan Hugenbruch
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Joanna K Kowalska
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Christopher J Pollock
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Frederico A Lima
- Centro Nacional de Pesquisa em Energia e Materiais, Laboratório Nacional de Luz Síncrotron, Rua Giuseppe Máximo Scolfaro 10000, Campinas, SP, 13083-970, Brazil
| | - Kenneth D Finkelstein
- Cornell High Energy Synchrotron Source, Wilson Laboratory, Cornell University, Ithaca, NY, 14853, USA
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany.
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA.
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