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Haga N, Ishida T. A Triplet/Singlet Ground-State Switch via the Steric Inhibition of Conjugation in 4,6-Bis(trifluoromethyl)-1,3-phenylene Bisnitroxide. Molecules 2023; 29:70. [PMID: 38202653 PMCID: PMC10779647 DOI: 10.3390/molecules29010070] [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: 10/30/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Ground triplet 4,6-bis(trifluoromethyl)-1,3-phenylene bis(tert-butyl nitroxide) (TF2PBN) reacted with [Y(hfac)3(H2O)2] (hfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dionate), affording a doubly hydrogen-bonded adduct [Y(hfac)3(H2O)2(TF2PBN)]. The biradical was recovered from the adduct through recrystallization. Crystallographic analysis indicates that the torsion angles (|θ| ≤ 90°) between the benzene ring and nitroxide groups were 74.9 and 84.8° in the adduct, which are larger than those of the starting material TF2PBN. Steric congestion due to o-trifluoromethyl groups gives rise to the reduction of π-conjugation. Two hydrogen bonds enhance this deformation. Susceptometry of the adduct indicates a ground singlet with 2J/kB = -128(2) K, where 2J corresponds to the singlet-triplet gap. The observed magneto-structure relation is qualitatively consistent with Rajca's pioneering work. A density functional theory calculation at the UB3LYP/6-311+G(2d,p) level using the atomic coordinates determined provided a result of 2J/kB = -162.3 K for the adduct, whilst the corresponding calculation on intact TF2PBN provided +87.2 K. After a comparison among a few known compounds, the 2J vs. |θ| plot shows a negative slope with a critical torsion of 65(3)°. The ferro- and antiferromagnetic coupling contributions are balanced in TF2PBN, being responsible for ground-state interconversion by means of small structural perturbation like hydrogen bonds.
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Affiliation(s)
| | - Takayuki Ishida
- Department of Engineering Science, The University of Electro-Communications, Chofu 182-8585, Tokyo Prefecture, Japan
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2
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Zhang F, Zhang Z, Zhao Y, Du C, Li Y, Gao J, Ren X, Ma T, Li B, Bu Y. Redox-Regulated Magnetic Conversions between Ferro- and Antiferromagnetism in Organic Nitroxide Diradicals. Molecules 2023; 28:6232. [PMID: 37687060 PMCID: PMC10488413 DOI: 10.3390/molecules28176232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/07/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Redox-induced magnetic transformation in organic diradicals is an appealing phenomenon. In this study, we theoretically designed twelve couples of diradicals in which two nitroxide (NO) radical groups are connected to the redox-active couplers including p-benzoquinonyl, 1,4-naphthoquinyl, 9,10-anthraquinonyl, naphthacene-5,12-dione, pentacene-6,13-dione, hexacene-6,15-dione, pyrazinyl, quinoxalinyl, phenazinyl, 5,12-diazanaphthacene, 6,13-diazapentacene, and 6,15-diazahexacene. As evidenced at both the B3LYP and M06-2X levels of theory, the calculations reveal that the magnetic reversal can take place from ferromagnetism to antiferromagnetism, or vice versa, by means of redox method in these designed organic magnetic molecules. It was observed that p-benzoquinonyl, 1,4-naphthoquinyl, 9,10-anthraquinonyl, naphthacene-5,12-dione, pentacene-6,13-dione, and hexacene-6,15-dione-bridged NO diradicals produce antiferromagnetism while their dihydrogenated counterparts exhibit ferromagnetism. Similarly, pyrazinyl, quinoxalinyl, phenazinyl, 5,12-diazanaphthacene, 6,13-diazapentacene, and 6,15-diazahexacene-bridged NO diradicals present ferromagnetism while their dihydrogenated counterparts show antiferromagnetism. The differences in the magnetic behaviors and magnetic magnitudes of each of the twelve couples of diradicals could be attributed to their distinctly different spin-interacting pathways. It was found that the nature of the coupler and the length of the coupling path are important factors in controlling the magnitude of the magnetic exchange coupling constant J. Specifically, smaller HOMO-LUMO (HOMO: highest occupied molecular orbital, LUMO: lowest unoccupied molecular orbital) gaps of the couplers and shorter coupler lengths, as well as shorter linking bond lengths, can attain stronger magnetic interactions. In addition, a diradical with an extensively π-conjugated structure is beneficial to spin transport and can effectively promote magnetic coupling, yielding a large |J| accordingly. That is, a larger spin polarization can give rise to a stronger magnetic interaction. The sign of J for these studied diradicals can be predicted from the spin alternation rule, the shape of the singly occupied molecular orbitals (SOMOs), and the SOMO-SOMO energy gaps of the triplet state. This study paves the way for the rational design of magnetic molecular switches.
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Affiliation(s)
- Fengying Zhang
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Zijun Zhang
- Department of Chemistry and Chemical Engineering, Jinzhong University, Jinzhong 030619, China;
| | - Yali Zhao
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Chao Du
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Yong Li
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Jiaqi Gao
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Xiaobo Ren
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Teng Ma
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Boqiong Li
- Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China; (C.D.); (Y.L.); (J.G.); (X.R.); (T.M.); (B.L.)
- Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong 030619, China
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China;
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Wang M, Zhao J, Su F, Xu H. An Ab initio study of double-electron oxidized base pairs with diradical character through ring-expansion modification. COMPUT THEOR CHEM 2019. [DOI: 10.1016/j.comptc.2019.112539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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La Porte NT, Christensen JA, Krzyaniak MD, Rugg BK, Wasielewski MR. Spin-Selective Photoinduced Electron Transfer within Naphthalenediimide Diradicals. J Phys Chem B 2019; 123:7731-7739. [DOI: 10.1021/acs.jpcb.9b06303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Nathan T. La Porte
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Joseph A. Christensen
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Matthew D. Krzyaniak
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Brandon K. Rugg
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael R. Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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5
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Zhao P, Bu Y. Remarkable Differences in Spin Couplings for Various Self-Paired Dimers of Ring-Expansion-Radicalized Uracil: A Basis for the Design of Magnetically Anisotropic Assemblies. Chemphyschem 2018; 19:208-219. [PMID: 29165931 DOI: 10.1002/cphc.201701068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Indexed: 11/09/2022]
Abstract
The spin-coupling properties of a series of radicalized uracil (rU) dimer diradicals with different H-bonding modes is examined. Each rU has four double H-bonding sites [the amide units: two at the Watson-Crick face (upper site WC1 and lower site WC2 ), a Hoogsteen site (HO), and a minor-groove site (MI)], and ten homogeneous dimers (rU-rU) can self-pair with well-defined diradical characters and comparable stability to the native U dimers. More interestingly, all these dimers exhibit distinctly different spin-coupling characters (ferromagnetic (FM) versus antiferromagnetic (AFM) and large- versus small-magnitude spin couplings), indicative of remarkable magnetic-coupling anisotropy of rU. This observation originates from the fusion of a cyclopentadienyl radical to U, which leads to uneven spin-density distribution. In rU, the fused five-membered radical ring can spin-polarize to the edge in the minor groove, and thus dimerization of rU leads to different H-bonded structures with remarkably different magnetic couplings. The calculated larger magnetic coupling constants J are 1003.7 and 540.2 cm-1 for the WC2 -HO and MI-HO H-bonding modes between rU, which exhibit considerably large FM couplings, the MI-MI, WC1 -WC2 and WC2 -WC2 modes show moderate FM couplings (J=0.4-77 cm-1 ), and the other modes exhibit moderate or weak AFM couplings. These observations indicate that the HO and MI sites are favorable spin-coupling sites. In addition, the H-bond lengths and electronic structures of the H-bonding sites, proton transfer, and extra H-bonding interaction with the surroundings can also affect the magnetic couplings of the base pairs. Clearly, the unique magnetic coupling anisotropy of rU provides a promising application basis for the design and assembly of bio-inspired anisotropically magnetic membranes and even magnetism-tunable building blocks for novel magnetic nanoscale devices.
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Affiliation(s)
- Peiwen Zhao
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China.,School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, P. R. China
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6
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Barone V, Cacelli I, Ferretti A. The role of the multiconfigurational character of nitronyl-nitroxide in the singlet–triplet energy gap of its diradicals. Phys Chem Chem Phys 2018; 20:18547-18555. [DOI: 10.1039/c8cp02165a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
CAS(2,2) reference may not be sufficient for the computation of singlet–triplet energy gap by DDCI.
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Affiliation(s)
| | - Ivo Cacelli
- Dipartimento di Chimica e Chimica Industriale
- Università di Pisa
- Pisa
- Italy
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)
| | - Alessandro Ferretti
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)
- Area della Ricerca
- I-56124 Pisa
- Italy
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7
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Barone V, Cacelli I, Ferretti A, Prampolini G. Magnetic gaps in organic tri-radicals: From a simple model to accurate estimates. J Chem Phys 2017; 146:104103. [DOI: 10.1063/1.4977598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Barone V, Cacelli I, Ferretti A, Prampolini G. Quantitative prediction and interpretation of spin energy gaps in polyradicals: the virtual magnetic balance. Phys Chem Chem Phys 2017; 19:9039-9044. [DOI: 10.1039/c7cp00186j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Open-shell organic molecules possessing more than two unpaired electrons and sufficient stability at room temperature are very unusual, but some of them were recently synthesized and promise a number of fascinating applications.
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Affiliation(s)
| | - Ivo Cacelli
- Dipartimento di Chimica e Chimica Industriale
- Università di Pisa
- Pisa
- Italy
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)
| | - Alessandro Ferretti
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)
- Area della Ricerca
- I-56124 Pisa
- Italy
| | - Giacomo Prampolini
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)
- Area della Ricerca
- I-56124 Pisa
- Italy
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9
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Sinha Ray S, Ghosh A, Chattopadhyay S, Chaudhuri RK. Taming the Electronic Structure of Diradicals through the Window of Computationally Cost Effective Multireference Perturbation Theory. J Phys Chem A 2016; 120:5897-916. [DOI: 10.1021/acs.jpca.6b03211] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Suvonil Sinha Ray
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | - Anirban Ghosh
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | - Rajat K. Chaudhuri
- Theoretical Physics, Indian Institute of Astrophysics, Bangalore 560034, India
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10
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Zhang F, Feng Y, Song X, Bu Y. Computational insights into intriguing vibration-induced pulsing diradical character in perfluoropentacene and the perfluorination effect. Phys Chem Chem Phys 2016; 18:16179-87. [PMID: 27250923 DOI: 10.1039/c6cp01706a] [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
As an n-type organic semiconductor compound, perfluoropentacene has more widespread applications in organic electronics because of its higher electron mobility compared with its parent pentacene. Herein, we explore intriguing dynamic electronic properties of perfluoropentacene caused by structural vibrations using density functional theory calculations. Perfluoropentacene could exhibit diradical character because of the persistent vibrations, although it belongs to a closed-shell singlet molecule in its equilibrium configuration. Not all the vibration-induced structural changes can induce diradical character, but only those leading to a small singlet-triplet energy gap, especially the small HOMO-LUMO gap, as well as the short cross-linking C-C bonds and distorted carbon ring structures in polyacetylene chains make great contributions. Due to molecular vibrations, the diradical character of dynamic perfluoropentacene exhibits pulsing behavior. Compared with pentacene, its perfluorination can not only considerably stabilize two frontier molecular orbitals, but also reduce the HOMO-LUMO gap, thus leading to an increase of the number of vibrational modes which can make the diradical character appear. In particular, perfluorination makes 19 diradical vibrational modes appear in the low frequency region. These observations indicate that some low energy pulses can trigger perfluoropentacene molecular vibrations according to some low energy modes and thus the appearance of pulsing diradical character or molecular magnetism. Clearly, the observed novel characters of a molecule possessing hidden pulsing diradical character and tunable magnetism in this work would contribute to opening up promising areas for designing peculiar magnetic materials.
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Affiliation(s)
- Fengying Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
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11
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Cacelli I, Ferretti A, Prampolini G, Barone V. BALOO: A Fast and Versatile Code for Accurate Multireference Variational/Perturbative Calculations. J Chem Theory Comput 2015; 11:2024-35. [DOI: 10.1021/ct501071k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ivo Cacelli
- Dipartimento
di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi
3, I-56124 Pisa, Pisa, Italy
- Istituto di Chimica
dei Composti OrganoMetallici (ICCOM-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Pisa, Italy
| | - Alessandro Ferretti
- Istituto di Chimica
dei Composti OrganoMetallici (ICCOM-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Pisa, Italy
| | - Giacomo Prampolini
- Istituto di Chimica
dei Composti OrganoMetallici (ICCOM-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56125 Pisa, Pisa, Italy
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13
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Yang H, Chen M, Song X, Bu Y. Structural fluctuation governed dynamic diradical character in pentacene. Phys Chem Chem Phys 2015; 17:13904-14. [DOI: 10.1039/c5cp00902b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Energy field-induced structural fluctuation can not only induce potential diradical character but also modulate its dynamical behavior in pentacene.
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Affiliation(s)
- Hongfang Yang
- School of Chemistry and Chemical Engineering
- Shandong University
- Jinan
- P. R. China
| | - Mengzhen Chen
- School of Chemistry and Chemical Engineering
- Shandong University
- Jinan
- P. R. China
| | - Xinyu Song
- School of Chemistry and Chemical Engineering
- Shandong University
- Jinan
- P. R. China
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering
- Shandong University
- Jinan
- P. R. China
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14
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Cacelli I, Ferretti A, Prampolini G. Perturbative Multireference Configuration Interaction (CI-MRPT2) Calculations in a Focused Dynamical Approach: A Computational Study of Solvatochromism in Pyrimidine. J Phys Chem A 2014; 119:5250-9. [DOI: 10.1021/jp509877q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ivo Cacelli
- Dipartimento
di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi
3, I-56124 Pisa, Italy
- Area della Ricerca, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Alessandro Ferretti
- Area della Ricerca, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Giacomo Prampolini
- Area della Ricerca, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), via G. Moruzzi 1, I-56124 Pisa, Italy
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Ali ME, Staemmler V, Illas F, Oppeneer PM. Designing the Redox-Driven Switching of Ferro- to Antiferromagnetic Couplings in Organic Diradicals. J Chem Theory Comput 2013; 9:5216-20. [DOI: 10.1021/ct400886w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Md. Ehesan Ali
- Department
of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
| | - Volker Staemmler
- Center
for Theoretical Chemistry, Ruhr-Universität Bochum, D-44801 Bochum, Germany
| | - Francesc Illas
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain
| | - Peter M. Oppeneer
- Department
of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
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