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Alías-Rodríguez M, Huix-Rotllant M. Control of Iron(II)-Tris(2,2'-Bipyridine) Light-Induced Excited-State Trapping via External Electromagnetic Fields. Chemphyschem 2024; 25:e202400471. [PMID: 38797713 DOI: 10.1002/cphc.202400471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 05/29/2024]
Abstract
Light-induced excited spin-state trapping reactions in iron pyridinic complexes allow the iron's low-to-high spin transition in a sub-picosecond timescale. Employing a recently developed model for [Fe(2,2'-bipyridine)3]2+ photochemical spin-crossover reaction in conjunction with quantum wavepacket dynamics, we explore the possibility of controlling the reaction through external electromagnetic fields, aiming at stabilizing the initial metal-to-ligand charge transfer states. We show that simple Gaussian-shaped electromagnetic fields have a minor effect on the population kinetics. However, introducing vibrationally excited initial wavepacket representations allows for maintaining the population trapped in the metal-to-ligand charge transfer states. Using optimal control theory, we propose an electromagnetic field shape that increases the lifetime of metal-to-ligand charge transfer states. These results open the route for controlling the iron photochemistry through the action of external electric fields.
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2
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Troß J, Arias-Martinez JE, Carter-Fenk K, Cole-Filipiak NC, Schrader P, McCaslin LM, Head-Gordon M, Ramasesha K. Femtosecond Core-Level Spectroscopy Reveals Involvement of Triplet States in the Gas-Phase Photodissociation of Fe(CO) 5. J Am Chem Soc 2024; 146:22711-22723. [PMID: 39092878 DOI: 10.1021/jacs.4c07523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Excitation of iron pentacarbonyl [Fe(CO)5], a prototypical photocatalyst, at 266 nm causes the sequential loss of two CO ligands in the gas phase, creating catalytically active, unsaturated iron carbonyls. Despite numerous studies, major aspects of its ultrafast photochemistry remain unresolved because the early excited-state dynamics have so far eluded spectroscopic observation. This has led to the long-held assumption that ultrafast dissociation of gas-phase Fe(CO)5 proceeds exclusively on the singlet manifold. Herein, we present a combined experimental-theoretical study employing ultrafast extreme ultraviolet transient absorption spectroscopy near the Fe M2,3-edge, which features spectral evolution on 100 fs and 3 ps time scales, alongside high-level electronic structure theory, which enables characterization of the molecular geometries and electronic states involved in the ultrafast photodissociation of Fe(CO)5. We assign the 100 fs evolution to spectroscopic signatures associated with intertwined structural and electronic dynamics on the singlet metal-centered states during the first CO loss and the 3 ps evolution to the competing dissociation of Fe(CO)4 along the lowest singlet and triplet surfaces to form Fe(CO)3. Calculations of transient spectra in both singlet and triplet states as well as spin-orbit coupling constants along key structural pathways provide evidence for intersystem crossing to the triplet ground state of Fe(CO)4. Thus, our work presents the first spectroscopic detection of transient excited states during ultrafast photodissociation of gas-phase Fe(CO)5 and challenges the long-standing assumption that triplet states do not play a role in the ultrafast dynamics.
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Affiliation(s)
- Jan Troß
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Juan E Arias-Martinez
- Kenneth S. Pitzer Center for Theoretical Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Kevin Carter-Fenk
- Kenneth S. Pitzer Center for Theoretical Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Neil C Cole-Filipiak
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Paul Schrader
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Laura M McCaslin
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Krupa Ramasesha
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
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3
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Terek S, Milovanović M. Ab initio multireference calculation of electronic spectra of the osmium complexes, [Os(bpy) 3 ] 2 + and [Os(phen) 3 ] 2 + . J Comput Chem 2024; 45:1750-1761. [PMID: 38647342 DOI: 10.1002/jcc.27372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/22/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024]
Abstract
The spin-orbit coupling corrected absorption spectra of osmium complexes, [Os(bpy) 3 ] 2 + and [Os(phen) 3 ] 2 + , were calculated by using ab initio multireference perturbation method (NEVPT2) with relativistic effects taken into account throughout ZORA approximation and corresponding all-electron basis sets. For the same purpose, the time-dependent DFT techniques were used. A very good agreement between NEVPT2 and experimental spectra should be highlighted, especially for the MLCT transitions that occur in visible and near-UV regions ( 16 , 000 - 33 , 000 cm - 1 ). Moreover, the present study offers description of excited states of titled osmium complexes and their spectra interpretation using molecular orbitals.
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Affiliation(s)
- Saša Terek
- Faculty of Physical Chemistry, University of Belgrade, Belgrade, Serbia
| | - Milan Milovanović
- Faculty of Physical Chemistry, University of Belgrade, Belgrade, Serbia
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Alías-Rodríguez M, Bhattacharyya S, Huix-Rotllant M. Ultrafast Spin Crossover Photochemical Mechanism in [Fe II(2,2'-bipyridine) 3] 2+] Revealed by Quantum Dynamics. J Phys Chem Lett 2023; 14:8571-8576. [PMID: 37725036 DOI: 10.1021/acs.jpclett.3c02201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Photoexcitation of [FeII(2,2'-bipyridine)3]2+ induces a subpicosecond spin crossover transformation from a low-spin singlet to a high-spin quintet state. The mechanism involves metal-centered (MC) and metal-ligand charge transfer (MLCT) triplet intermediates, but their individual contributions to this efficient intersystem crossing have been object of debate. Employing quantum wavepacket dynamics, we show that MC triplets are catalyzing the transfer to the high-spin state. This photochemical pathway is made possible thanks to bipyridine stretching vibrations, facilitating the conversion between the MLCT bands to such MC triplets. We show that the lifetime of the MLCT states can be increased to tens of picoseconds by breaking the conjugation between pyridine units, which increases the energetic gap between MLCT and MC states. This opens the route for the design of new chelating ligands inducing long-lived MLCT states in iron complexes.
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5
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Iuchi S, Koga N. Ultrafast Electronic Relaxation in Aqueous [Fe(bpy) 3] 2+: A Surface Hopping Study. J Phys Chem Lett 2023; 14:4225-4232. [PMID: 37126354 DOI: 10.1021/acs.jpclett.3c00686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Trajectory surface hopping simulations are performed to better understand the electronic relaxation dynamics of [Fe(bpy)3]2+ in aqueous solution. Specifically, the ultrafast relaxation from the photoexcited singlet metal-to-ligand charge-transfer (MLCT) to the metastable quintet metal-centered (MC) states is simulated through the surface hopping method, where the MLCT and MC states of [Fe(bpy)3]2+ in aqueous solution are computed by using a model electronic Hamiltonian developed previously. As a result, most of the trajectories are interpreted to show the sequential relaxation pathways via the triplet MC states, though some are the direct pathway from MLCT to the quintet MC states. Even though the triplet MC states are involved in the relaxation, the population transfer to the singlet MC ground state is very small, and the population of the quintet MC states reaches more than ∼96%, reasonably consistent with the unity quantum efficiency discussed experimentally.
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Affiliation(s)
- Satoru Iuchi
- Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Nobuaki Koga
- Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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6
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Yazdani S, Phillips J, Ekanayaka TK, Cheng R, Dowben PA. The Influence of the Substrate on the Functionality of Spin Crossover Molecular Materials. Molecules 2023; 28:molecules28093735. [PMID: 37175145 PMCID: PMC10180229 DOI: 10.3390/molecules28093735] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Spin crossover complexes are a route toward designing molecular devices with a facile readout due to the change in conductance that accompanies the change in spin state. Because substrate effects are important for any molecular device, there are increased efforts to characterize the influence of the substrate on the spin state transition. Several classes of spin crossover molecules deposited on different types of surface, including metallic and non-metallic substrates, are comprehensively reviewed here. While some non-metallic substrates like graphite seem to be promising from experimental measurements, theoretical and experimental studies indicate that 2D semiconductor surfaces will have minimum interaction with spin crossover molecules. Most metallic substrates, such as Au and Cu, tend to suppress changes in spin state and affect the spin state switching process due to the interaction at the molecule-substrate interface that lock spin crossover molecules in a particular spin state or mixed spin state. Of course, the influence of the substrate on a spin crossover thin film depends on the molecular film thickness and perhaps the method used to deposit the molecular film.
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Affiliation(s)
- Saeed Yazdani
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Jared Phillips
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Thilini K Ekanayaka
- Department of Physics and Astronomy, Jorgensen Hall, University of Nebraska, Lincoln, NE 68588-0299, USA
| | - Ruihua Cheng
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Peter A Dowben
- Department of Physics and Astronomy, Jorgensen Hall, University of Nebraska, Lincoln, NE 68588-0299, USA
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7
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Ahoulou S, Richart C, Carteret C, Pillet S, Vilà N, Walcarius A. Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes. Molecules 2022; 27:molecules27175444. [PMID: 36080210 PMCID: PMC9458166 DOI: 10.3390/molecules27175444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 11/16/2022] Open
Abstract
Iron (II) tris(2,2′-bipyridine) complexes, [Fe(bpy)3]2+, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H2O)6]2+ species by hydrogen bonds to the anionic sulfonate moieties grafted to the silica nanopores. In a first step, thiol-based silica films have been electrochemically generated on indium tin oxide (ITO) substrates by co-condensation of 3-mercaptopropyltrimethoxysilane (MPTMS) and tetraethoxysilane (TEOS). Secondly, the thiol function has been modified to sulfonate by chemical oxidation using hydrogen peroxide in acidic medium as an oxidizing agent. The immobilization of [Fe(bpy)3]2+ complexes has been performed in situ in two consecutive steps: (i) impregnation of the sulfonate functionalized silica films in an aqueous solution of iron (II) sulfate heptahydrate; (ii) dipping of the iron-containing mesostructures in a solution of bipyridine ligands in acetonitrile. The in situ formation of the [Fe(bpy)3]2+ complex is evidenced by its characteristic optical absorption spectrum, and elemental composition analysis using X-ray photoelectron spectroscopy. The measured optical and electrochemical properties of immobilized [Fe(bpy)3]2+ complexes are not altered by confinement in the nanostructured silica thin film.
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Affiliation(s)
- Samuel Ahoulou
- LCPME, CNRS, Universite de Lorraine, F-54000 Nancy, France
- CRM2, CNRS, Universite de Lorraine, F-54000 Nancy, France
| | - Clara Richart
- LCPME, CNRS, Universite de Lorraine, F-54000 Nancy, France
| | | | - Sébastien Pillet
- CRM2, CNRS, Universite de Lorraine, F-54000 Nancy, France
- Correspondence: (S.P.); (N.V.); (A.W.)
| | - Neus Vilà
- LCPME, CNRS, Universite de Lorraine, F-54000 Nancy, France
- Correspondence: (S.P.); (N.V.); (A.W.)
| | - Alain Walcarius
- LCPME, CNRS, Universite de Lorraine, F-54000 Nancy, France
- Correspondence: (S.P.); (N.V.); (A.W.)
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8
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Karmakar S, Chakraborty P, Saha-Dasgupta T. Trend in light-induced excited-state spin trapping in Fe(II)-based spin crossover systems. Phys Chem Chem Phys 2022; 24:10201-10209. [PMID: 35420090 DOI: 10.1039/d2cp00539e] [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
A computational study of the light-induced excited spin-state trapping (LIESST) in a number of Fe(II) spin crossover complexes, coordinated by monodentate, bidentate and multidentate ligands is carried out, with the goal to uncover the trend in the low temperature relaxation rate. A nine order of magnitude change in low temperature relaxation rate is observed among the complexes. The trend is rationalized in terms of the change in metal-ligand covalency, numerically estimated by the crystal orbital Hamiltonian population, thus influencing the back donation or delocalization of the electrons from the low-lying Fe(II)-centered molecular orbital to the empty low-lying ligand-centered π* antibonding molecular orbitals.
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Affiliation(s)
- Shiladitya Karmakar
- Department of Condensed Matter Physics and Materials Science, S. N. Bose National Centre for Basic Sciences, Kolkata 700 106, India.
| | - Pradip Chakraborty
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Tanusri Saha-Dasgupta
- Department of Condensed Matter Physics and Materials Science, S. N. Bose National Centre for Basic Sciences, Kolkata 700 106, India.
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9
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Finney BA, Chowdhury SR, Kirkvold C, Vlaisavljevich B. CASPT2 molecular geometries of Fe(II) spin-crossover complexes. Phys Chem Chem Phys 2022; 24:1390-1398. [PMID: 34981806 DOI: 10.1039/d1cp04885f] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Using fully internally contracted (FIC)-CASPT2 analytical gradients, geometry optimizations of spin-crossover complexes are reported. This approach is tested on a series of Fe(II) complexes with different sizes, ranging from 13 to 61 atoms. A combination of active space and basis set choices are employed to investigate their role in determining reliable molecular geometries. The reported strategy demonstrates that a wave function-based level of theory can be used to optimize the geometries of metal complexes in reasonable times and enables one to treat the molecular geometry and electronic structure of the complexes using the same level of theory. For a series of smaller Fe(II) SCO complexes, strong field ligands in the LS state result in geometries with the largest differences between DFT and CASPT2; however, good agreement overall is observed between DFT and CASPT2. For the larger complexes, moderate sized basis sets yield geometries that compare well with DFT and available experimental data. We recommend using the (10e,12o) active space since convergence to a minimum structure was more efficient than with truncated active spaces despite having similar Fe-ligand bond distances.
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Affiliation(s)
- Brian A Finney
- University of South Dakota, Department of Chemistry, 414 E Clark St., Vermillion SD, 57069, USA.
| | - Sabyasachi Roy Chowdhury
- University of South Dakota, Department of Chemistry, 414 E Clark St., Vermillion SD, 57069, USA.
| | - Clara Kirkvold
- University of South Dakota, Department of Chemistry, 414 E Clark St., Vermillion SD, 57069, USA.
| | - Bess Vlaisavljevich
- University of South Dakota, Department of Chemistry, 414 E Clark St., Vermillion SD, 57069, USA.
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10
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Gaffney KJ. Capturing photochemical and photophysical transformations in iron complexes with ultrafast X-ray spectroscopy and scattering. Chem Sci 2021; 12:8010-8025. [PMID: 34194691 PMCID: PMC8208315 DOI: 10.1039/d1sc01864g] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/25/2021] [Indexed: 12/31/2022] Open
Abstract
Light-driven chemical transformations provide a compelling approach to understanding chemical reactivity with the potential to use this understanding to advance solar energy and catalysis applications. Capturing the non-equilibrium trajectories of electronic excited states with precision, particularly for transition metal complexes, would provide a foundation for advancing both of these objectives. Of particular importance for 3d metal compounds is characterizing the population dynamics of charge-transfer (CT) and metal-centered (MC) electronic excited states and understanding how the inner coordination sphere structural dynamics mediate the interaction between these states. Recent advances in ultrafast X-ray laser science has enabled the electronic excited state dynamics in 3d metal complexes to be followed with unprecedented detail. This review will focus on simultaneous X-ray emission spectroscopy (XES) and X-ray solution scattering (XSS) studies of iron coordination and organometallic complexes. These simultaneous XES-XSS studies have provided detailed insight into the mechanism of light-induced spin crossover in iron coordination compounds, the interaction of CT and MC excited states in iron carbene photosensitizers, and the mechanism of Fe-S bond dissociation in cytochrome c.
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Affiliation(s)
- Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
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11
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Barlow K, Johansson JO. Ultrafast photoinduced dynamics in Prussian blue analogues. Phys Chem Chem Phys 2021; 23:8118-8131. [DOI: 10.1039/d1cp00535a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A review on ultrafast photoinduced processes in molecule-based magnets with an emphasis on Prussian blue analogues.
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Affiliation(s)
- Kyle Barlow
- EaStCHEM School of Chemistry
- University of Edinburgh
- David Brewster Road
- Edinburgh
- UK
| | - J. Olof Johansson
- EaStCHEM School of Chemistry
- University of Edinburgh
- David Brewster Road
- Edinburgh
- UK
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12
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Iuchi S, Koga N. A model electronic Hamiltonian to describe low-lying d-d and metal-to-ligand charge-transfer excited states of [Fe(bpy) 3 ] 2. J Comput Chem 2020; 42:166-179. [PMID: 33146893 DOI: 10.1002/jcc.26444] [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: 09/18/2020] [Revised: 10/16/2020] [Accepted: 10/16/2020] [Indexed: 11/10/2022]
Abstract
A simple practical method to compute both d-d and metal-to-ligand charge-transfer (MLCT) excited states of iron(II) polypyridyl complexes is proposed for use in simulation studies. Specifically, a model electronic Hamiltonian developed previously for d-d excited states of [Fe(bpy)3 ]2+ is extended to deal with low-lying MLCT excited states simultaneously by including the MLCT electronic configurations into the basis functions of the model Hamiltonian. As a first attempt, parameters in the model Hamiltonian matrix elements are determined by using density functional theory (DFT) and time-dependent (TD-)DFT calculation results as benchmarks. To examine the performance of the model Hamiltonian, the potential energy curves along the interpolation between the lowest singlet and quintet state structures are compared to those from the (TD-)DFT calculations and to those from CASPT2 calculations in literature. The electronic absorption spectrum computed through molecular dynamics simulation is compared to the experimental spectrum. The spin-orbit couplings at the ground state structure are also compared to those from wavefunction-based ab initio electronic structure calculations. The results indicate that the constructed model Hamiltonian provides reasonable information on both the low-lying d-d and MLCT excited states of [Fe(bpy)3 ]2+ .
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Affiliation(s)
- Satoru Iuchi
- Graduate School of Informatics, Nagoya University, Nagoya, Japan
| | - Nobuaki Koga
- Graduate School of Informatics, Nagoya University, Nagoya, Japan
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13
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Tran LN, Neuscamman E. Improving Excited-State Potential Energy Surfaces via Optimal Orbital Shapes. J Phys Chem A 2020; 124:8273-8279. [DOI: 10.1021/acs.jpca.0c07593] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Lan Nguyen Tran
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Ho Chi Minh City Institute of Physics, VAST, Ho Chi Minh City 700000, Vietnam
| | - Eric Neuscamman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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14
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Kunnus K, Li L, Titus CJ, Lee SJ, Reinhard ME, Koroidov S, Kjær KS, Hong K, Ledbetter K, Doriese WB, O'Neil GC, Swetz DS, Ullom JN, Li D, Irwin K, Nordlund D, Cordones AA, Gaffney KJ. Chemical control of competing electron transfer pathways in iron tetracyano-polypyridyl photosensitizers. Chem Sci 2020; 11:4360-4373. [PMID: 34122894 PMCID: PMC8159445 DOI: 10.1039/c9sc06272f] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/15/2020] [Indexed: 12/15/2022] Open
Abstract
Photoinduced intramolecular electron transfer dynamics following metal-to-ligand charge-transfer (MLCT) excitation of [Fe(CN)4(2,2'-bipyridine)]2- (1), [Fe(CN)4(2,3-bis(2-pyridyl)pyrazine)]2- (2) and [Fe(CN)4(2,2'-bipyrimidine)]2- (3) were investigated in various solvents with static and time-resolved UV-Visible absorption spectroscopy and Fe 2p3d resonant inelastic X-ray scattering (RIXS). This series of polypyridyl ligands, combined with the strong solvatochromism of the complexes, enables the 1MLCT vertical energy to be varied from 1.64 eV to 2.64 eV and the 3MLCT lifetime to range from 180 fs to 67 ps. The 3MLCT lifetimes in 1 and 2 decrease exponentially as the MLCT energy increases, consistent with electron transfer to the lowest energy triplet metal-centred (3MC) excited state, as established by the Tanabe-Sugano analysis of the Fe 2p3d RIXS data. In contrast, the 3MLCT lifetime in 3 changes non-monotonically with MLCT energy, exhibiting a maximum. This qualitatively distinct behaviour results from a competing 3MLCT → ground state (GS) electron transfer pathway that exhibits energy gap law behaviour. The 3MLCT → GS pathway involves nuclear tunnelling for the high-frequency polypyridyl breathing mode (hν = 1530 cm-1), which is most displaced for complex 3, making this pathway significantly more efficient. Our study demonstrates that the excited state relaxation mechanism of Fe polypyridyl photosensitizers can be readily tuned by ligand and solvent environment. Furthermore, our study reveals that extending charge transfer lifetimes requires control of the relative energies of the 3MLCT and the 3MC states and suppression of the intramolecular distortion of the acceptor ligand in the 3MLCT excited state.
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Affiliation(s)
- Kristjan Kunnus
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Lin Li
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Charles J Titus
- Department of Physics, Stanford University Stanford California 94305 USA
| | - Sang Jun Lee
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Marco E Reinhard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Sergey Koroidov
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kasper S Kjær
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kiryong Hong
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kathryn Ledbetter
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
- Department of Physics, Stanford University Stanford California 94305 USA
| | | | - Galen C O'Neil
- National Institute of Standards and Technology Boulder CO 80305 USA
| | - Daniel S Swetz
- National Institute of Standards and Technology Boulder CO 80305 USA
| | - Joel N Ullom
- National Institute of Standards and Technology Boulder CO 80305 USA
| | - Dale Li
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Kent Irwin
- Department of Physics, Stanford University Stanford California 94305 USA
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Dennis Nordlund
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Amy A Cordones
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
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15
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Controlling the Lifetime of the Triplet MLCT State in Fe(II) Polypyridyl Complexes through Ligand Modification. INORGANICS 2020. [DOI: 10.3390/inorganics8020016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A computational study is presented in which two strategies of ligand modifications have been explored to invert the relative energy of the metal-to-ligand charge transfer (MLCT) and metal-centered (MC) state in Fe(II)-polypyridyl complexes. Replacing the bipyridines by stronger σ donors increases the ligand-field strength and pushes the MC state to higher energy, while the use of ligands with a larger π conjugation leads to lower MLCT energies.
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16
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Megow S, Fitschen HL, Tuczek F, Temps F. Ultrafast Photodynamics of an Azopyridine-Functionalized Iron(II) Complex: Implications for the Concept of Ligand-Driven Light-Induced Spin Change. J Phys Chem Lett 2019; 10:6048-6054. [PMID: 31549841 DOI: 10.1021/acs.jpclett.9b02083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on the ultrafast photodynamics of an iron(II) complex with a photoisomerizable pentadentate azo-tetrapyridylamino ligand after irradiation with ultraviolet light. The results of femtosecond transient electronic absorption spectroscopy performed on the low-spin (LS) form of the title complex show that initial excitation of the ππ* state of the azopyridine unit in the ligand at λpump = 312 nm is followed by an ultrafast intersystem crossing (ISC) that leads to the formation of a metal-centered (MC) 5T state, in competition with the intended photoswitching of the azopyridine unit. Additional measurements carried out upon excitation of the singlet metal-to-ligand charge-transfer (1MLCT) transition at λpump = 455 nm suggest that this energy transfer occurs via an MLCT state. The resulting high-spin (HS) 5T state of the complex is metastable and recovers to the LS ground state with a time constant of ∼3 ns. The implications of these observations on the ligand-driven light-induced spin change concept are discussed.
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Affiliation(s)
- Sebastian Megow
- Institut für Physikalische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
| | - Henrike-Leonie Fitschen
- Institut für Anorganische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
| | - Felix Tuczek
- Institut für Anorganische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
| | - Friedrich Temps
- Institut für Physikalische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
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17
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Britz A, Gawelda W, Assefa TA, Jamula LL, Yarranton JT, Galler A, Khakhulin D, Diez M, Harder M, Doumy G, March AM, Bajnóczi É, Németh Z, Pápai M, Rozsályi E, Sárosiné Szemes D, Cho H, Mukherjee S, Liu C, Kim TK, Schoenlein RW, Southworth SH, Young L, Jakubikova E, Huse N, Vankó G, Bressler C, McCusker JK. Using Ultrafast X-ray Spectroscopy To Address Questions in Ligand-Field Theory: The Excited State Spin and Structure of [Fe(dcpp)2]2+. Inorg Chem 2019; 58:9341-9350. [DOI: 10.1021/acs.inorgchem.9b01063] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Alexander Britz
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Wojciech Gawelda
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - Tadesse A. Assefa
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Institute of Laser Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Lindsey L. Jamula
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jonathan T. Yarranton
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | | | - Dmitry Khakhulin
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Michael Diez
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Manuel Harder
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Anne Marie March
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Éva Bajnóczi
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | - Zoltán Németh
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | - Mátyás Pápai
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
- Department of Chemistry, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Emese Rozsályi
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | | | - Hana Cho
- Center for Analytical Chemistry, Division of Chemical and Medical Metrology, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
| | - Sriparna Mukherjee
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Chang Liu
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Tae Kyu Kim
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| | - Robert W. Schoenlein
- Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - Stephen H. Southworth
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Physics and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Nils Huse
- Center for Free-Electron Laser Science, University of Hamburg, 22607 Hamburg, Germany
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - György Vankó
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | - Christian Bressler
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - James K. McCusker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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18
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Kjær KS, Van Driel TB, Harlang TCB, Kunnus K, Biasin E, Ledbetter K, Hartsock RW, Reinhard ME, Koroidov S, Li L, Laursen MG, Hansen FB, Vester P, Christensen M, Haldrup K, Nielsen MM, Dohn AO, Pápai MI, Møller KB, Chabera P, Liu Y, Tatsuno H, Timm C, Jarenmark M, Uhlig J, Sundstöm V, Wärnmark K, Persson P, Németh Z, Szemes DS, Bajnóczi É, Vankó G, Alonso-Mori R, Glownia JM, Nelson S, Sikorski M, Sokaras D, Canton SE, Lemke HT, Gaffney KJ. Finding intersections between electronic excited state potential energy surfaces with simultaneous ultrafast X-ray scattering and spectroscopy. Chem Sci 2019; 10:5749-5760. [PMID: 31293761 PMCID: PMC6568243 DOI: 10.1039/c8sc04023k] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 04/21/2019] [Indexed: 12/12/2022] Open
Abstract
Combined X-ray free-electron laser techniques pinpoints loci of intersections between potential energy surfaces of a photo-excited 3d transition-metal centered molecule.
Light-driven molecular reactions are dictated by the excited state potential energy landscape, depending critically on the location of conical intersections and intersystem crossing points between potential surfaces where non-adiabatic effects govern transition probabilities between distinct electronic states. While ultrafast studies have provided significant insight into electronic excited state reaction dynamics, experimental approaches for identifying and characterizing intersections and seams between electronic states remain highly system dependent. Here we show that for 3d transition metal systems simultaneously recorded X-ray diffuse scattering and X-ray emission spectroscopy at sub-70 femtosecond time-resolution provide a solid experimental foundation for determining the mechanistic details of excited state reactions. In modeling the mechanistic information retrieved from such experiments, it becomes possible to identify the dominant trajectory followed during the excited state cascade and to determine the relevant loci of intersections between states. We illustrate our approach by explicitly mapping parts of the potential energy landscape dictating the light driven low-to-high spin-state transition (spin crossover) of [Fe(2,2′-bipyridine)3]2+, where the strongly coupled nuclear and electronic dynamics have been a source of interest and controversy. We anticipate that simultaneous X-ray diffuse scattering and X-ray emission spectroscopy will provide a valuable approach for mapping the reactive trajectories of light-triggered molecular systems involving 3d transition metals.
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Affiliation(s)
- Kasper S Kjær
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ; .,Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark.,Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Tim B Van Driel
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Tobias C B Harlang
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark.,Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Kristjan Kunnus
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Elisa Biasin
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Kathryn Ledbetter
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Robert W Hartsock
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Marco E Reinhard
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Sergey Koroidov
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Lin Li
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Mads G Laursen
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Frederik B Hansen
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Peter Vester
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Morten Christensen
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Kristoffer Haldrup
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Martin M Nielsen
- Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Asmus O Dohn
- Science Institute , University of Iceland , 107 Reykjavík , Iceland
| | - Mátyás I Pápai
- Science Institute , University of Iceland , 107 Reykjavík , Iceland.,Wigner Research Centre for Physics , Hungarian Academy of Sciences , P.O. Box 49 , H-1525 Budapest , Hungary
| | - Klaus B Møller
- Science Institute , University of Iceland , 107 Reykjavík , Iceland
| | - Pavel Chabera
- Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Yizhu Liu
- Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden.,Centre for Analysis and Synthesis , Department of Chemistry , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Hideyuki Tatsuno
- Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Cornelia Timm
- Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Martin Jarenmark
- Department of Geology , Department of Chemistry , Lund University , 223 62 Lund , Sweden
| | - Jens Uhlig
- Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Villy Sundstöm
- Department of Chemical Physics , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis , Department of Chemistry , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Petter Persson
- Theoretical Chemistry Division , Department of Chemistry , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Zoltán Németh
- Wigner Research Centre for Physics , Hungarian Academy of Sciences , P.O. Box 49 , H-1525 Budapest , Hungary
| | - Dorottya Sárosiné Szemes
- Wigner Research Centre for Physics , Hungarian Academy of Sciences , P.O. Box 49 , H-1525 Budapest , Hungary
| | - Éva Bajnóczi
- Wigner Research Centre for Physics , Hungarian Academy of Sciences , P.O. Box 49 , H-1525 Budapest , Hungary
| | - György Vankó
- Wigner Research Centre for Physics , Hungarian Academy of Sciences , P.O. Box 49 , H-1525 Budapest , Hungary
| | - Roberto Alonso-Mori
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - James M Glownia
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Silke Nelson
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Marcin Sikorski
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Dimosthenis Sokaras
- SSRL , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Sophie E Canton
- ELI-ALPS , ELI-HU Non-Profit Ltd. , Dugonics ter 13 , Szeged 6720 , Hungary.,FS-ATTO , Deutsches Elektronen-Synchrotron (DESY) , Notkestrasse 85 , D-22607 Hamburg , Germany
| | - Henrik T Lemke
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA.,SwissFEL , Paul Scherrer Institut , Villigen PSI 5232 , Switzerland
| | - Kelly J Gaffney
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ; .,SSRL , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
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19
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Zhang Y, Bennett K, Mukamel S. Monitoring Ultrafast Spin Crossover Intermediates in an Iron(II) Complex by Broad Band Stimulated X-ray Raman Spectroscopy. J Phys Chem A 2018; 122:6524-6531. [PMID: 29944375 DOI: 10.1021/acs.jpca.8b01762] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photoinduced spin crossover dynamics of transition metal complexes is of fundamental scientific importance and is used for sensor device applications and solar energy harvesting. Current X-ray and optical spectroscopy experiments for [FeII(bpy)3], an archetypal earth-abundant metal complex, show conflicting spin dynamics. We have simulated the broad band transient X-ray absorption and hybrid (broad + narrow band) X-ray stimulated Raman signals at the N and Fe K-edges of the key excited state intermediates involved in the spin crossover process of this complex. We find that these signals are much more sensitive to electron and spin populations than transition absorption and may be useful in the design of photovoltaic and artificial photosynthetic systems.
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Affiliation(s)
- Yu Zhang
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Kochise Bennett
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Shaul Mukamel
- Department of Chemistry , University of California , Irvine , California 92697 , United States
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20
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Ashley DC, Jakubikova E. Ray-Dutt and Bailar Twists in Fe(II)-Tris(2,2′-bipyridine): Spin States, Sterics, and Fe–N Bond Strengths. Inorg Chem 2018; 57:5585-5596. [DOI: 10.1021/acs.inorgchem.8b00560] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Daniel C. Ashley
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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21
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Sousa C, Domingo A, de Graaf C. Effect of Second-Order Spin-Orbit Coupling on the Interaction between Spin States in Spin-Crossover Systems. Chemistry 2018; 24:5146-5152. [PMID: 29143986 DOI: 10.1002/chem.201704854] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/14/2017] [Indexed: 11/10/2022]
Abstract
The second-order spin-orbit coupling is evaluated in two transition-metal complexes to establish the effect on the deactivation mechanism of the excited low-spin state in systems that undergo spin transitions under the influence of light. We compare the standard perturbational approach to calculate the second-order interaction with a variational strategy based on the effective Hamiltonian theory and show that the former one can only be applied in some special cases and even then gives results that largely overestimate the interaction. The combined effect of geometry distortions and second-order spin-orbit coupling leads to sizeable interactions for states that are nearly uncoupled in the symmetric (average) structure of the complex. This opens the possibility of a direct deactivation from the singlet and triplet states of the metal-to-ligand charge-transfer manifold to the final high-spin state as suggested from the interpretation of experimental data but so far not supported by theoretical descriptions of the light-induced spin crossover.
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Affiliation(s)
- Carmen Sousa
- Departament de Química Física, Institut de Química Teòrica i Computacional, Universitat de Barcelona, C/ Martí i Franquès 1, 08028, Barcelona, Spain
| | - Alex Domingo
- Departament de Química Fsica i Inorgànica, Universitat Rovira i Virgili, Marcel⋅lí Domingo s/n, 43007, Tarragona, Spain
| | - Coen de Graaf
- Departament de Química Fsica i Inorgànica, Universitat Rovira i Virgili, Marcel⋅lí Domingo s/n, 43007, Tarragona, Spain.,ICREA, Pg. Lluis Companys 23, 08010, Barcelona, Spain
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22
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Sousa C, de Graaf C, Rudavskyi A, Broer R. Theoretical Study of the Light-Induced Spin Crossover Mechanism in [Fe(mtz)6]2+ and [Fe(phen)3]2+. J Phys Chem A 2017; 121:9720-9727. [DOI: 10.1021/acs.jpca.7b10687] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Carmen Sousa
- Departament
de Ciència de Materials i Química Física and
Institut de Química Teòrica i Computacional, Universitat de Barcelona, C/Martí i Franquès 1, 08028 Barcelona, Catalunya, Spain
| | - Coen de Graaf
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Catalunya, Spain
- Departament
de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Catalunya, Spain
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Andrii Rudavskyi
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ria Broer
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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23
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De S, Tewary S, Garnier D, Li Y, Gontard G, Lisnard L, Flambard A, Breher F, Boillot ML, Rajaraman G, Lescouëzec R. Solution and Solid-State Study of the Spin-Crossover [FeII
(R-bik)3
](BF4
)2
Complexes (R = Me, Et, Vinyl). Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201701013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Siddhartha De
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
| | - Subrata Tewary
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Powai, Mumbai Maharashtra India
| | - Delphine Garnier
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
- Institut für Anorganische Chemie; Karlsruhe Institut für Technologie (KIT); Campus Süd, Engesserstr. 15, Geb. 30.45 76131 Karlsruhe Germany
| | - Yanling Li
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
| | - Geoffrey Gontard
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
| | - Laurent Lisnard
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
| | - Alexandrine Flambard
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
| | - Frank Breher
- Institut für Anorganische Chemie; Karlsruhe Institut für Technologie (KIT); Campus Süd, Engesserstr. 15, Geb. 30.45 76131 Karlsruhe Germany
| | - Marie-Laure Boillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay; Univ. Paris Sud, Université Paris-Saclay, CNRS; 91405 Orsay CEDEX France
| | - Gopalan Rajaraman
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Powai, Mumbai Maharashtra India
| | - Rodrigue Lescouëzec
- Institut Parisien de Chimie Moléculaire (UMR 8232); Université Paris 06, Sorbonne Universités; 4 Place Jussieu 75252 Paris CEDEX 5 France
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24
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Chergui M, Collet E. Photoinduced Structural Dynamics of Molecular Systems Mapped by Time-Resolved X-ray Methods. Chem Rev 2017; 117:11025-11065. [DOI: 10.1021/acs.chemrev.6b00831] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Majed Chergui
- Laboratoire
de Spectroscopie Ultrarapide (LSU), ISIC, and Lausanne Centre for
Ultrafast Science (LACUS), Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Eric Collet
- Univ Rennes 1, CNRS, Institut de Physique de Rennes, UMR 6251, UBL, Rennes F-35042, France
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25
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Kjær KS, Zhang W, Alonso-Mori R, Bergmann U, Chollet M, Hadt RG, Hartsock RW, Harlang T, Kroll T, Kubiček K, Lemke HT, Liang HW, Liu Y, Nielsen MM, Robinson JS, Solomon EI, Sokaras D, van Driel TB, Weng TC, Zhu D, Persson P, Wärnmark K, Sundström V, Gaffney KJ. Ligand manipulation of charge transfer excited state relaxation and spin crossover in [Fe(2,2'-bipyridine) 2(CN) 2]. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:044030. [PMID: 28653021 PMCID: PMC5461172 DOI: 10.1063/1.4985017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 05/21/2017] [Indexed: 05/11/2023]
Abstract
We have used femtosecond resolution UV-visible and Kβ x-ray emission spectroscopy to characterize the electronic excited state dynamics of [Fe(bpy)2(CN)2], where bpy=2,2'-bipyridine, initiated by metal-to-ligand charge transfer (MLCT) excitation. The excited-state absorption in the transient UV-visible spectra, associated with the 2,2'-bipyridine radical anion, provides a robust marker for the MLCT excited state, while the transient Kβ x-ray emission spectra provide a clear measure of intermediate and high spin metal-centered excited states. From these measurements, we conclude that the MLCT state of [Fe(bpy)2(CN)2] undergoes ultrafast spin crossover to a metal-centered quintet excited state through a short lived metal-centered triplet transient species. These measurements of [Fe(bpy)2(CN)2] complement prior measurement performed on [Fe(bpy)3]2+ and [Fe(bpy)(CN)4]2- in dimethylsulfoxide solution and help complete the chemical series [Fe(bpy)N(CN)6-2N]2N-4, where N = 1-3. The measurements confirm that simple ligand modifications can significantly change the relaxation pathways and excited state lifetimes and support the further investigation of light harvesting and photocatalytic applications of 3d transition metal complexes.
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Affiliation(s)
| | | | - Roberto Alonso-Mori
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Uwe Bergmann
- PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Matthieu Chollet
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ryan G Hadt
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | | | | | | | | | - Henrik T Lemke
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | - Yizhu Liu
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Martin M Nielsen
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Joseph S Robinson
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | - Dimosthenis Sokaras
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | | | - Diling Zhu
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Petter Persson
- Division of Theoretical Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Kenneth Wärnmark
- Center for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Villy Sundström
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
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26
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Ashley DC, Jakubikova E. Ironing out the photochemical and spin-crossover behavior of Fe(II) coordination compounds with computational chemistry. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.02.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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27
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Shee NK, Drew MGB, Datta D. Isolation of a metal-to-ligand charge-transfer (MLCT) state of a tris 1,4-diimine complex of iron in the solid state: X-ray crystal structure and EPR. NEW J CHEM 2017. [DOI: 10.1039/c6nj02874h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using 5,6-dihydro-5,6-epoxy-1,10-phenanthroline as the ligand L, the X-ray crystal structure of [FeL3](ClO4)2·2H2O is determined.
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Affiliation(s)
- Nirmal K. Shee
- Department of Inorganic Chemistry
- Indian Association for the Cultivation of Science
- Calcutta 700 032
- India
| | | | - Dipankar Datta
- Department of Inorganic Chemistry
- Indian Association for the Cultivation of Science
- Calcutta 700 032
- India
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28
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Zhang W, Kjær KS, Alonso-Mori R, Bergmann U, Chollet M, Fredin LA, Hadt RG, Hartsock RW, Harlang T, Kroll T, Kubiček K, Lemke HT, Liang HW, Liu Y, Nielsen MM, Persson P, Robinson JS, Solomon EI, Sun Z, Sokaras D, van Driel TB, Weng TC, Zhu D, Wärnmark K, Sundström V, Gaffney KJ. Manipulating charge transfer excited state relaxation and spin crossover in iron coordination complexes with ligand substitution. Chem Sci 2016; 8:515-523. [PMID: 28451198 PMCID: PMC5341207 DOI: 10.1039/c6sc03070j] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/24/2016] [Indexed: 12/11/2022] Open
Abstract
Optical and X-ray free-electron laser measurements reveal ligand substitution in an Fe(ii)-centered complex extends its MLCT lifetime.
Developing light-harvesting and photocatalytic molecules made with iron could provide a cost effective, scalable, and environmentally benign path for solar energy conversion. To date these developments have been limited by the sub-picosecond metal-to-ligand charge transfer (MLCT) electronic excited state lifetime of iron based complexes due to spin crossover – the extremely fast intersystem crossing and internal conversion to high spin metal-centered excited states. We revitalize a 30 year old synthetic strategy for extending the MLCT excited state lifetimes of iron complexes by making mixed ligand iron complexes with four cyanide (CN–) ligands and one 2,2′-bipyridine (bpy) ligand. This enables MLCT excited state and metal-centered excited state energies to be manipulated with partial independence and provides a path to suppressing spin crossover. We have combined X-ray Free-Electron Laser (XFEL) Kβ hard X-ray fluorescence spectroscopy with femtosecond time-resolved UV-visible absorption spectroscopy to characterize the electronic excited state dynamics initiated by MLCT excitation of [Fe(CN)4(bpy)]2–. The two experimental techniques are highly complementary; the time-resolved UV-visible measurement probes allowed electronic transitions between valence states making it sensitive to ligand-centered electronic states such as MLCT states, whereas the Kβ fluorescence spectroscopy provides a sensitive measure of changes in the Fe spin state characteristic of metal-centered excited states. We conclude that the MLCT excited state of [Fe(CN)4(bpy)]2– decays with roughly a 20 ps lifetime without undergoing spin crossover, exceeding the MLCT excited state lifetime of [Fe(2,2′-bipyridine)3]2+ by more than two orders of magnitude.
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Affiliation(s)
- Wenkai Zhang
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Kasper S Kjær
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ; .,Department of Chemical Physics , Lund University , P.O. Box 12 4 , 22100 Lund , Sweden.,Centre for Molecular Movies , Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Roberto Alonso-Mori
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Uwe Bergmann
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ; .,LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Matthieu Chollet
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Lisa A Fredin
- Theoretical Chemistry Division , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Ryan G Hadt
- Department of Chemistry , Stanford University , Stanford , California 94305 , USA
| | - Robert W Hartsock
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ; .,Department of Chemistry , Stanford University , Stanford , California 94305 , USA
| | - Tobias Harlang
- Department of Chemical Physics , Lund University , P.O. Box 12 4 , 22100 Lund , Sweden
| | - Thomas Kroll
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA.,Department of Chemistry , Stanford University , Stanford , California 94305 , USA
| | - Katharina Kubiček
- Max Planck Institute for Biophysical Chemistry , 37077 , Göttingen , Germany
| | - Henrik T Lemke
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Huiyang W Liang
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ; .,LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Yizhu Liu
- Department of Chemical Physics , Lund University , P.O. Box 12 4 , 22100 Lund , Sweden
| | - Martin M Nielsen
- Centre for Molecular Movies , Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Petter Persson
- Theoretical Chemistry Division , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Joseph S Robinson
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Edward I Solomon
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA.,Department of Chemistry , Stanford University , Stanford , California 94305 , USA
| | - Zheng Sun
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
| | - Dimosthenis Sokaras
- SSRL , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Tim B van Driel
- Centre for Molecular Movies , Department of Physics , Technical University of Denmark , DK-2800 , Lyngby , Denmark
| | - Tsu-Chien Weng
- SSRL , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Diling Zhu
- LCLS , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , USA
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis , Department of Chemistry , Lund University , P.O. Box 124 , 22100 Lund , Sweden
| | - Villy Sundström
- Department of Chemical Physics , Lund University , P.O. Box 12 4 , 22100 Lund , Sweden
| | - Kelly J Gaffney
- PULSE Institute , SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , USA . ;
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29
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Field R, Liu LC, Gawelda W, Lu C, Miller RJD. Spectral Signatures of Ultrafast Spin Crossover in Single Crystal [FeII
(bpy)3
](PF6
)2. Chemistry 2016; 22:5118-22. [DOI: 10.1002/chem.201600374] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Ryan Field
- Departments of Chemistry and Physics; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
- The Hamburg Centre for Ultrafast Imaging; Centre for Free Electron Laser Science; Max Planck Institute for the Structure and Dynamics of Matter; Bld. 99, Luruper Chaussee 149 22761 Hamburg Germany
| | - Lai Chung Liu
- Departments of Chemistry and Physics; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
- The Hamburg Centre for Ultrafast Imaging; Centre for Free Electron Laser Science; Max Planck Institute for the Structure and Dynamics of Matter; Bld. 99, Luruper Chaussee 149 22761 Hamburg Germany
| | | | - Cheng Lu
- Departments of Chemistry and Physics; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
| | - R. J. Dwayne Miller
- Departments of Chemistry and Physics; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
- The Hamburg Centre for Ultrafast Imaging; Centre for Free Electron Laser Science; Max Planck Institute for the Structure and Dynamics of Matter; Bld. 99, Luruper Chaussee 149 22761 Hamburg Germany
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30
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Saureu S, de Graaf C. TD-DFT study of the light-induced spin crossover of Fe(iii) complexes. Phys Chem Chem Phys 2016; 18:1233-44. [DOI: 10.1039/c5cp06620d] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Two light-induced spin-crossover Fe(iii) compounds have been studied with time-dependent density functional theory (TD-DFT) to investigate the deactivation mechanism and the role of the ligand-field states as intermediates in this process.
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Affiliation(s)
- Sergi Saureu
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- 43007 Tarragona
- Spain
| | - Coen de Graaf
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- 43007 Tarragona
- Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA)
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31
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Iuchi S, Koga N. Insight into the light-induced spin crossover of [Fe(bpy)3]2+ in aqueous solution from molecular dynamics simulation of d–d excited states. Phys Chem Chem Phys 2016; 18:4789-99. [DOI: 10.1039/c5cp06406f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lifetimes of triplet d–d states were evaluated through molecular dynamics simulations to gain insight into relaxation dynamics of aqueous [Fe(bpy)3]2+.
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Affiliation(s)
- Satoru Iuchi
- Graduate School of Information Science
- Nagoya University
- Nagoya 464-8601
- Japan
| | - Nobuaki Koga
- Graduate School of Information Science
- Nagoya University
- Nagoya 464-8601
- Japan
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32
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Nance J, Bowman DN, Mukherjee S, Kelley CT, Jakubikova E. Insights into the Spin-State Transitions in [Fe(tpy)2]2+: Importance of the Terpyridine Rocking Motion. Inorg Chem 2015; 54:11259-68. [DOI: 10.1021/acs.inorgchem.5b01747] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James Nance
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - David N. Bowman
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - Sriparna Mukherjee
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - C. T. Kelley
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department of Mathematics and ‡Department of
Chemistry, North Carolina State University (NCSU), Raleigh, North Carolina 27695, United States
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33
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Bowman DN, Bondarev A, Mukherjee S, Jakubikova E. Tuning the Electronic Structure of Fe(II) Polypyridines via Donor Atom and Ligand Scaffold Modifications: A Computational Study. Inorg Chem 2015; 54:8786-93. [DOI: 10.1021/acs.inorgchem.5b01409] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David N. Bowman
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Alexey Bondarev
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Sriparna Mukherjee
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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34
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Angnes RA, Li Z, Correia CRD, Hammond GB. Recent synthetic additions to the visible light photoredox catalysis toolbox. Org Biomol Chem 2015; 13:9152-67. [PMID: 26242759 DOI: 10.1039/c5ob01349f] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The boom in visible light photoredox catalysis (VLPC) research has demonstrated that this novel synthetic approach is here to stay. VLPC enables reactive radical intermediates to be catalytically generated at ambient temperature, a feat not generally allowed through traditional pyrolysis- or radical initiator-based methodologies. VLPC has vastly extended the range of substrates and reaction schemes that have been traditionally the domain of radical reactions. In this review the photophysics background of VLPC will be briefly discussed, followed by a report on recent inroads of VLPC into decarboxylative couplings and radical C-H functionalization of aromatic compounds. The bulk of the review will be dedicated to advances in synergistic catalysis involving VLPC, namely the combination of photoredox catalysis with organocatalysis, including β-functionalization of carbonyl groups, functionalization of weak aliphatic C-H bonds, and anti-Markovnikov hydrofunctionalization of alkenes; dual catalysis with gold or with nickel, photoredox catalysis as an oxidation promoter in transition metal catalysis, and acid-catalyzed enantioselective radical addition to π systems.
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Affiliation(s)
- Ricardo A Angnes
- Chemistry Institute, State University of Campinas - Unicamp C.P. 6154, CEP. 13083-970, Campinas, São Paulo, Brazil
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35
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Abstract
It is known that excitation by visible light of the singlet metal-to-ligand charge-transfer ((1)MLCT) states of Fe(II) complexes leads to population of the lowest-lying high-spin quintet state ((5)T) with unity quantum yield. Here we investigate this so-called spin crossover (SCO) transition in aqueous iron(II)tris(bipyridine). We use pump-probe transient absorption spectroscopy with a high time resolution of <60 fs in the ultraviolet probe range, in which the (5)T state absorbs, and of <40 fs in the visible probe range, in which both the hot MLCT state and the (5)T state absorb. Our results show that the (5)T state is impulsively populated in less than 50 fs, which is the time we measured for the depopulation of the MCLT manifold. We propose that non-totally-symmetric modes mediate the process, possibly high-frequency modes of the bipyridine (bpy) ligand. These results show that even though the SCO process in Fe(II) complexes represents a strongly spin-forbidden (ΔS = 2) two-electron transition, spin flipping occurs at near subvibrational times and is intertwined with the electron and structural dynamics of the system.
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Affiliation(s)
- Gerald Auböck
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, Faculté des Sciences de Base, ISIC, Lausanne CH-1015, Switzerland
| | - Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, Faculté des Sciences de Base, ISIC, Lausanne CH-1015, Switzerland
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36
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Zhang W, Gaffney KJ. Mechanistic studies of photoinduced spin crossover and electron transfer in inorganic complexes. Acc Chem Res 2015; 48:1140-8. [PMID: 25789406 DOI: 10.1021/ar500407p] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Electronic excited-state phenomena provide a compelling intersection of fundamental and applied research interests in the chemical sciences. This holds true for coordination chemistry, where harnessing the strong optical absorption and photocatalytic activity of compounds depends on our ability to control fundamental physical and chemical phenomena associated with the nonadiabatic dynamics of electronic excited states. The central events of excited-state chemistry can critically influence the dynamics of electronic excited states, including internal conversion (transitions between distinct electronic states) and intersystem crossing (transitions between electronic states with different spin multiplicities), events governed by nonadiabatic interactions between electronic states in close proximity to conical intersections, as well as solvation and electron transfer. The diversity of electronic and nuclear dynamics also makes the robust interpretation of experimental measurements challenging. Developments in theory, simulation, and experiment can all help address the interpretation and understanding of chemical dynamics in organometallic and coordination chemistry. Synthesis presents the opportunity to chemically engineer the strength and symmetry of the metal-ligand interactions. This chemical control can be exploited to understand the influence of electronic ground state properties on electronic excited-state dynamics. New time-resolved experimental methods and the insightful exploitation of established methods have an important role in understanding, and ideally controlling, the photophysics and photochemistry of transition metal complexes. Techniques that can disentangle the coupled motion of electrons and nuclear dynamics warrant emphasis. We present a review of electron localization dynamics in charge transfer excited states and the dynamics of photoinitiated spin crossover dynamics. Both electron localization and spin crossover have been investigated by numerous research groups with femtosecond resolution spectroscopy, but challenges in experimental interpretation have left significant uncertainty about the molecular properties that control these phenomena. Our Account will emphasize how tailoring the experimental probe, femtosecond resolution vibrational anisotropy for electron localization, and femtosecond resolution hard X-ray fluorescence for spin crossover can make a significant impact on the interpretability of experimental measurements. The emphasis on thorough and robust interpretation has also led to an emphasis on simpler molecular systems. This enables iteration between experiment and theory, a requirement for the development of a more predictive understanding of electronic excited-state phenomena and an essential step to the development of design rules for solar materials.
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Affiliation(s)
- Wenkai Zhang
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kelly J. Gaffney
- Stanford
Synchrotron Radiation Laboratory and PULSE Institute, SLAC National
Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
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37
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Abstract
The properties of transition metal complexes are interesting not only for their potential applications in solar energy conversion, OLEDs, molecular electronics, biology, photochemistry, etc. but also for their fascinating photophysical properties that call for a rethinking of fundamental concepts. With the advent of ultrafast spectroscopy over 25 years ago and, more particularly, with improvements in the past 10-15 years, a new area of study was opened that has led to insightful observations of the intramolecular relaxation processes such as internal conversion (IC), intersystem crossing (ISC), and intramolecular vibrational redistribution (IVR). Indeed, ultrafast optical spectroscopic tools, such as fluorescence up-conversion, show that in many cases, intramolecular relaxation processes can be extremely fast and even shorter than time scales of vibrations. In addition, more and more examples are appearing showing that ultrafast ISC rates do not scale with the magnitude of the metal spin-orbit coupling constant, that is, that there is no heavy-atom effect on ultrafast time scales. It appears that the structural dynamics of the system and the density of states play a crucial role therein. While optical spectroscopy delivers an insightful picture of electronic relaxation processes involving valence orbitals, the photophysics of metal complexes involves excitations that may be centered on the metal (called metal-centered or MC) or the ligand (called ligand-centered or LC) or involve a transition from one to the other or vice versa (called MLCT or LMCT). These excitations call for an element-specific probe of the photophysics, which is achieved by X-ray absorption spectroscopy. In this case, transitions from core orbitals to valence orbitals or higher allow probing the electronic structure changes induced by the optical excitation of the valence orbitals, while also delivering information about the geometrical rearrangement of the neighbor atoms around the atom of interest. With the emergence of new instruments such as X-ray free electron lasers (XFELs), it is now possible to perform ultrafast laser pump/X-ray emission probe experiments. In this case, one probes the density of occupied states. These core-level spectroscopies and other emerging ones, such as photoelectron spectroscopy of solutions, are delivering a hitherto unseen degree of detail into the photophysics of metal-based molecular complexes. In this Account, we will give examples of applications of the various methods listed above to address specific photophysical processes.
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Affiliation(s)
- Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie
Ultrarapide, ISIC, Faculté des Sciences de Base, Station 6, CH-1015 Lausanne, Switzerland
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38
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Alcover-Fortuny G, de Graaf C, Caballol R. Spin-crossover in phenylazopyridine-functionalized Ni–porphyrin: trans–cis isomerization triggered by π–π interactions. Phys Chem Chem Phys 2015; 17:217-25. [DOI: 10.1039/c4cp04402a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To elucidate the light-induced spin-crossover mechanism of the PAPy-functionalized Ni(ii)–porphyrin, a DFT/CASSCF/CASPT2 study has been performed to determine the most stable cis and trans conformers and to characterize the excitation that triggers the process.
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Affiliation(s)
- Gerard Alcover-Fortuny
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- 43007 Tarragona
- Spain
| | - Coen de Graaf
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- 43007 Tarragona
- Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA)
| | - Rosa Caballol
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- 43007 Tarragona
- Spain
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39
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Vela S, Fumanal M, Ribas-Arino J, Robert V. Towards an accurate and computationally-efficient modelling of Fe(ii)-based spin crossover materials. Phys Chem Chem Phys 2015; 17:16306-14. [DOI: 10.1039/c5cp02502h] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A theoretical approach is proposed to accurately calculate the LS–HS energy gap of SCO complexes in the solid state.
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Affiliation(s)
- Sergi Vela
- Laboratoire de Chimie Quantique
- Université de Strasbourg
- F-67000 Strasbourg
- France
- Departament de Química Física and IQTCUB
| | - Maria Fumanal
- Departament de Química Física and IQTCUB
- Universitat de Barcelona
- Barcelona
- Spain
| | - Jordi Ribas-Arino
- Departament de Química Física and IQTCUB
- Universitat de Barcelona
- Barcelona
- Spain
| | - Vincent Robert
- Laboratoire de Chimie Quantique
- Université de Strasbourg
- F-67000 Strasbourg
- France
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40
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Vela S, Novoa JJ, Ribas-Arino J. Insights into the crystal-packing effects on the spin crossover of [FeII(1-bpp)]2+-based materials. Phys Chem Chem Phys 2014; 16:27012-24. [DOI: 10.1039/c4cp03971h] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Abstract
The study of spin crossover compounds by means of theoretical or experimental approaches has provided interesting results in recent decades. The main feature of such compounds is the change in the spin state induced by many different external stimuli, i.e. temperature, light, pressure, solvent coordination and the electric field. Spin crossover systems are potentially more useful than other magnetic molecules because their switching behaviour can occur closer to room temperature, and they are thus candidates for use in spintronic devices. Here, I review the state of the art in quantum chemical approaches to the study of such systems and discuss experiments that have focused on transport properties in single-molecule, nano-objects or thin-film spin crossover systems.
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Affiliation(s)
- Eliseo Ruiz
- Departament de Química Inorgànica and Centre de Recerca en Química Teòrica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
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42
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Domingo A, Sousa C, de Graaf C. The effect of thermal motion on the electron localization in metal-to-ligand charge transfer excitations in [Fe(bpy)3]2+. Dalton Trans 2014; 43:17838-46. [DOI: 10.1039/c4dt02294g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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43
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Escudero D, Thiel W. Assessing the density functional theory-based multireference configuration interaction (DFT/MRCI) method for transition metal complexes. J Chem Phys 2014; 140:194105. [DOI: 10.1063/1.4875810] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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Rudavskyi A, Sousa C, de Graaf C, Havenith RWA, Broer R. Computational approach to the study of thermal spin crossover phenomena. J Chem Phys 2014; 140:184318. [DOI: 10.1063/1.4875695] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Zhang W, Alonso-Mori R, Bergmann U, Bressler C, Chollet M, Galler A, Gawelda W, Hadt RG, Hartsock RW, Kroll T, Kjær KS, Kubiček K, Lemke HT, Liang HW, Meyer DA, Nielsen MM, Purser C, Robinson JS, Solomon EI, Sun Z, Sokaras D, van Driel TB, Vankó G, Weng TC, Zhu D, Gaffney KJ. Tracking excited-state charge and spin dynamics in iron coordination complexes. Nature 2014; 509:345-8. [PMID: 24805234 DOI: 10.1038/nature13252] [Citation(s) in RCA: 292] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 03/06/2014] [Indexed: 12/23/2022]
Abstract
Crucial to many light-driven processes in transition metal complexes is the absorption and dissipation of energy by 3d electrons. But a detailed understanding of such non-equilibrium excited-state dynamics and their interplay with structural changes is challenging: a multitude of excited states and possible transitions result in phenomena too complex to unravel when faced with the indirect sensitivity of optical spectroscopy to spin dynamics and the flux limitations of ultrafast X-ray sources. Such a situation exists for archetypal polypyridyl iron complexes, such as [Fe(2,2'-bipyridine)3](2+), where the excited-state charge and spin dynamics involved in the transition from a low- to a high-spin state (spin crossover) have long been a source of interest and controversy. Here we demonstrate that femtosecond resolution X-ray fluorescence spectroscopy, with its sensitivity to spin state, can elucidate the spin crossover dynamics of [Fe(2,2'-bipyridine)3](2+) on photoinduced metal-to-ligand charge transfer excitation. We are able to track the charge and spin dynamics, and establish the critical role of intermediate spin states in the crossover mechanism. We anticipate that these capabilities will make our method a valuable tool for mapping in unprecedented detail the fundamental electronic excited-state dynamics that underpin many useful light-triggered molecular phenomena involving 3d transition metal complexes.
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Affiliation(s)
- Wenkai Zhang
- PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA
| | - Roberto Alonso-Mori
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Uwe Bergmann
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | - Matthieu Chollet
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | | | - Ryan G Hadt
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Robert W Hartsock
- 1] PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA [2] Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Thomas Kroll
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Kasper S Kjær
- 1] Centre for Molecular Movies, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark [2] Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Katharina Kubiček
- 1] Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany [2] Deutsches Elektronen Synchrotron, Notkestraße 85, 22607 Hamburg, Germany
| | - Henrik T Lemke
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Huiyang W Liang
- 1] PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA [2] Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Drew A Meyer
- 1] PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA [2] Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Martin M Nielsen
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Carola Purser
- PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA
| | - Joseph S Robinson
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Edward I Solomon
- 1] Department of Chemistry, Stanford University, Stanford, California 94305, USA [2] SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Zheng Sun
- PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA
| | - Dimosthenis Sokaras
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Tim B van Driel
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - György Vankó
- Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest, Hungary
| | - Tsu-Chien Weng
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Diling Zhu
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Kelly J Gaffney
- PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA
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Iuchi S, Koga N. An improved model electronic Hamiltonian for potential energy surfaces and spin−orbit couplings of low-lying d−d states of [Fe(bpy)3]2+. J Chem Phys 2014; 140:024309. [DOI: 10.1063/1.4861229] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Saureu S, de Graaf C. On the role of solvent effects on the electronic transitions in Fe(II) and Ru(II) complexes. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2013.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sousa C, de Graaf C, Rudavskyi A, Broer R, Tatchen J, Etinski M, Marian CM. Ultrafast Deactivation Mechanism of the Excited Singlet in the Light‐Induced Spin Crossover of [Fe(2,2′‐bipyridine)
3
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2+. Chemistry 2013; 19:17541-51. [DOI: 10.1002/chem.201302992] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Carmen Sousa
- Departament de Química Física and Institut de Química, Teòrica i Computacional, Universitat de Barcelona, C/Martí i Franquès 1, 08028 Barcelona (Spain)
| | - Coen de Graaf
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel‐lí Domingo s/n, 43007 Tarragona (Spain), Fax: (+34)‐977559563
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona (Spain)
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Andrii Rudavskyi
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Ria Broer
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Jörg Tatchen
- Institute of Theoretical and Computational Chemistry, Heinrich‐Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf (Germany)
| | - Mihajlo Etinski
- Faculty of Physical Chemistry, University of Belgrade, Studentski Trg 12–16, 11158 Belgrade (Serbia)
| | - Christel M. Marian
- Institute of Theoretical and Computational Chemistry, Heinrich‐Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf (Germany)
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Malrieu JP, Caballol R, Calzado CJ, de Graaf C, Guihéry N. Magnetic interactions in molecules and highly correlated materials: physical content, analytical derivation, and rigorous extraction of magnetic Hamiltonians. Chem Rev 2013; 114:429-92. [PMID: 24102410 DOI: 10.1021/cr300500z] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jean Paul Malrieu
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse 3 , 118 route de Narbonne, 31062 Toulouse, France
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50
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Qu Y. Quantum-chemical investigation of the spin crossover complex [Fe(mbpzbpy)(NCS)2]. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 113:427-431. [PMID: 23747384 DOI: 10.1016/j.saa.2013.04.115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 04/19/2013] [Accepted: 04/24/2013] [Indexed: 06/02/2023]
Abstract
The geometries of the spin crossover complex [Fe(mbpzbpy)(NCS)2] were optimized by several density functionals and basis sets. In addition, the vibrational modes and IR spectra, excited states and UV/vis absorption spectra and spin splittings energies were also predicted by DFT/TD-DFT calculations.
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Affiliation(s)
- Yuhui Qu
- School of Chemistry and Chemical Engineering, Shandong Institute of Light Industry, Shandong, Jinan 250353, PR China.
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