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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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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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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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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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5
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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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Khakhulin D, Lawson Daku LM, Leshchev D, Newby GE, Jarenmark M, Bressler C, Wulff M, Canton SE. Visualizing the coordination-spheres of photoexcited transition metal complexes with ultrafast hard X-rays. Phys Chem Chem Phys 2019; 21:9277-9284. [DOI: 10.1039/c9cp01263j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The concept of coordination sphere (CS) is central to the rational development of hierarchical molecular assemblies in modern chemistry.
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Affiliation(s)
| | - L. M. Lawson Daku
- Département de Chimie Physique
- Université de Genève
- CH-1211 Genève 4
- Switzerland
| | - D. Leshchev
- European Synchrotron Radiation Facility (ESRF)
- 38000 Grenoble Cedex 9
- France
| | - G. E. Newby
- European Synchrotron Radiation Facility (ESRF)
- 38000 Grenoble Cedex 9
- France
| | - M. Jarenmark
- Department of Geology
- Lund University
- 223 62 Lund
- Sweden
- Lund University
| | | | - M. Wulff
- European Synchrotron Radiation Facility (ESRF)
- 38000 Grenoble Cedex 9
- France
| | - S. E. Canton
- ELI-ALPS
- ELI-HU Non-Profit Ltd
- Szeged 6720
- Hungary
- Attosecond Science Group
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7
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Sousa C, Alías M, Domingo A, de Graaf C. Deactivation of Excited States in Transition-Metal Complexes: Insight from Computational Chemistry. Chemistry 2018; 25:1152-1164. [DOI: 10.1002/chem.201801990] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Indexed: 11/11/2022]
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 Catalunya Spain
| | - Marc Alías
- Departament de Química Física i Inorgànica; Universitat Rovira i Virgili; Marcel⋅lí Domingo 1 43007 Tarragona Catalunya Spain
| | - Alex Domingo
- Departament de Química Física i Inorgànica; Universitat Rovira i Virgili; Marcel⋅lí Domingo 1 43007 Tarragona Catalunya Spain
| | - Coen de Graaf
- Departament de Química Física i Inorgànica; Universitat Rovira i Virgili; Marcel⋅lí Domingo 1 43007 Tarragona Catalunya Spain
- ICREA; Pg. Lluis Companys 23 08010 Barcelona Catalunya Spain
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Bibi N, de Arruda EGR, Domingo A, Oliveira AA, Galuppo C, Phung QM, Orra NM, Béron F, Paesano A, Pierloot K, Formiga ALB. Switching the Spin-Crossover Phenomenon by Ligand Design on Imidazole–Diazineiron(II) Complexes. Inorg Chem 2018; 57:14603-14616. [DOI: 10.1021/acs.inorgchem.8b02278] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Naheed Bibi
- Institute of Chemistry University of Campinas—UNICAMP, P.O. Box 6154, Campinas, São Paulo 13083-970, Brazil
| | | | - Alex Domingo
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven B-3001, Belgium
| | | | - Carolina Galuppo
- Institute of Chemistry University of Campinas—UNICAMP, P.O. Box 6154, Campinas, São Paulo 13083-970, Brazil
| | - Quan Manh Phung
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven B-3001, Belgium
| | - Naíma Mohammed Orra
- Institute of Chemistry University of Campinas—UNICAMP, P.O. Box 6154, Campinas, São Paulo 13083-970, Brazil
| | - Fanny Béron
- Institute of Physics Gleb Wataghin, University of Campinas—UNICAMP, Rua Sérgio Buarque de Holanda 777, Campinas, São Paulo 13083-859, Brazil
| | | | - Kristine Pierloot
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven B-3001, Belgium
| | - André Luiz Barboza Formiga
- Institute of Chemistry University of Campinas—UNICAMP, P.O. Box 6154, Campinas, São Paulo 13083-970, Brazil
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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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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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11
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Alcover-Fortuny G, Wu J, Caballol R, de Graaf C. Quantum Chemical Study of the Interligand Electron Transfer in Ru Polypyridyl Complexes. J Phys Chem A 2018; 122:1114-1123. [PMID: 29272128 DOI: 10.1021/acs.jpca.7b11422] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gerard Alcover-Fortuny
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Jianfang Wu
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Rosa Caballol
- Departament
de Química Fı́sica i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Coen de Graaf
- Departament
de Química Fı́sica 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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12
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Sousa C, Llunell M, Domingo A, de Graaf C. Theoretical evidence for the direct 3MLCT-HS deactivation in the light-induced spin crossover of Fe(ii)–polypyridyl complexes. Phys Chem Chem Phys 2018; 20:2351-2355. [DOI: 10.1039/c7cp08098k] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Second-order spin–orbit coupling and structural distortions activate the 3MLCT–5T2 deactivation in Fe(ii)–polypyridyl complexes.
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Affiliation(s)
- Carmen Sousa
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Miquel Llunell
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Alex Domingo
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- Campus Sescelades
- 43007 Tarragona
- Spain
| | - Coen de Graaf
- Departament de Química Física i Inorgànica
- Universitat Rovira i Virgili
- Campus Sescelades
- 43007 Tarragona
- Spain
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13
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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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14
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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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15
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Fumanal M, Capdevila-Cortada M, Ribas-Arino J, Novoa JJ. Electronic excitation energies in dimers between radical ions presenting long, multicenter bonding. J Chem Theory Comput 2015; 11:2651-60. [PMID: 26575562 DOI: 10.1021/acs.jctc.5b00381] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The formation of long, multicenter dimers between radical ions is usually monitored through UV-vis spectroscopy given the characteristic low-energy absorption band that they exhibit, not observed for the parent monomers. In this work, the performance of CASPT2, RASPT2, and TD-DFT methods for obtaining excitation energies of the long, multicenter bonded π-[TCNE]2(2-) and π-[TTF]2(2+) dimers has been addressed (TCNE = tetracyanoethylene; TTF = tetrathiafulvalene). The impact of the active space on the vertical electronic transitions computed at the RASPT2 and CASPT2 levels has been tested against experimentally observed absorption bands. Analogous tests have been carried out for a wide variety of density functionals within the TD-DFT formalism. Our calculations show that whereas CASPT2 predicts very accurate excitation energies for the π-[TCNE]2(2-), the mean absolute error for π-[TTF]2(2+) is higher for CASPT2 than for TD-DFT calculations, whenever pure density functionals or low % HF exchange hybrid functionals are used. Hybrid functionals with high % HF exchange (and thus RSH functionals) conduct to large errors on the excitation energies in both dimers. Furthermore, vertical electronic transitions are also obtained for 100 configurations extracted from a 45 ps molecular dynamics (CPMD) simulation aimed at providing an accurate description of the thermal fluctuation effects of a π-[TCNE]2(2-) dimer in dichloromethane. These thermal effects explain the shape of the experimental UV-vis spectrum, where the lowest HOMO → LUMO absorption presents a broad band and the following HOMO-1 → LUMO absorption exhibits a narrower band.
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Affiliation(s)
- Maria Fumanal
- Departament de Química Física and IQTCUB, Facultat de Química, Universitat de Barcelona , Avenida Diagonal 645, 08028 Barcelona, Spain
| | - Marçal Capdevila-Cortada
- Departament de Química Física and IQTCUB, Facultat de Química, Universitat de Barcelona , Avenida Diagonal 645, 08028 Barcelona, Spain
| | - Jordi Ribas-Arino
- Departament de Química Física and IQTCUB, Facultat de Química, Universitat de Barcelona , Avenida Diagonal 645, 08028 Barcelona, Spain
| | - Juan J Novoa
- Departament de Química Física and IQTCUB, Facultat de Química, Universitat de Barcelona , Avenida Diagonal 645, 08028 Barcelona, Spain
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