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Nicolini A, Anderlini B, Roncaglia F, Cornia A. An efficient transition-metal-free route to oligo- α-pyridylamines via fluoroarenes. CR CHIM 2023. [DOI: 10.5802/crchim.223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
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2
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Abe H, Yoshiichi Y, Kishimura H. Hydrogen/deuterium Exchange in 1-Alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide-based Solutions. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Gao P, Cai XP, Xie Q, Yang Q, Ou H, Wu WQ, Xu X, Xu Z, Lin X. Theoretical Studies on the Structures of Metal String Complexes Cr n(L) 4Cl 2 ( n = 3, 5, 7; L = Oligo-α-Pyridylamide) under the Effect of an Electric Field. Inorg Chem 2021; 60:9378-9386. [PMID: 34137268 DOI: 10.1021/acs.inorgchem.1c00206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To study the electronic structures and properties of [Crn(L)4Cl2] (n = 3, L = dpa: di(2-pyridyl)amido; n = 5, L = tpda: tripyridyldiamido; n = 7, L = teptra: tetrapyridyltriamine) metal string complexes, the BP86 method was used by considering the influence of the electric field (EF) applied parallel to the metal axis. As the EF increases, the migration of more positively charged Crodd is more significant than that of Creven, which results in alternating long-short Cr-Cr bonds. This happens because of the natural charges on the Crodd of 1-3, which are more electropositive than those on Creven. The electrons are pulled to the Cr and Cl(r) atoms at the high-potential side from Cl(l) at the low-potential side by the EF, which leads to asymmetrical FMOs. After the critical electric field (Ec), the configuration turns into a remarkably asymmetric one with alternating Cr-Cr quadruple bonds and weak interactions. The electrons are transferred from equatorial ligands (L) to metal chains. In the meantime, the asymmetry of the FMOs increases and the delocalization is further reduced, which affects the conductivity. Especially for [Cr7(teptra)4Cl2], the delocalized electrons of HOMO are completely transformed into a localized model after the critical electric field. It is observed that this supports the electric switching phenomenon ascribed to the conformations of delocalized and localized electrons. In addition, the longer the length of the metal chain, the smaller the Ec and the easier is for the complexes to be polarized by the EF.
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Affiliation(s)
- Pan Gao
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Xue-Ping Cai
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Qiongyi Xie
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Qingyun Yang
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Hong Ou
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Wei-Qing Wu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Xuan Xu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Zhiguang Xu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Xiaoming Lin
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
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Nicolini A, Affronte M, SantaLucia DJ, Borsari M, Cahier B, Caleffi M, Ranieri A, Berry JF, Cornia A. Tetrairon(II) extended metal atom chains as single-molecule magnets. Dalton Trans 2021; 50:7571-7589. [PMID: 33983354 PMCID: PMC8214398 DOI: 10.1039/d1dt01007g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Iron-based extended metal atom chains (EMACs) are potentially high-spin molecules with axial magnetic anisotropy and thus candidate single-molecule magnets (SMMs). We herein compare the tetrairon(ii), halide-capped complexes [Fe4(tpda)3Cl2] (1Cl) and [Fe4(tpda)3Br2] (1Br), obtained by reacting iron(ii) dihalides with [Fe2(Mes)4] and N2,N6-di(pyridin-2-yl)pyridine-2,6-diamine (H2tpda) in toluene, under strictly anhydrous and anaerobic conditions (HMes = mesitylene). Detailed structural, electrochemical and Mössbauer data are presented along with direct-current (DC) and alternating-current (AC) magnetic characterizations. DC measurements revealed similar static magnetic properties for the two derivatives, with χMT at room temperature above that for independent spin carriers, but much lower at low temperature. The electronic structure of the iron(ii) ions in each derivative was explored by ab initio (CASSCF-NEVPT2-SO) calculations, which showed that the main magnetic axis of all metals is directed close to the axis of the chain. The outer metals, Fe1 and Fe4, have an easy-axis magnetic anisotropy (D = -11 to -19 cm-1, |E/D| = 0.05-0.18), while the internal metals, Fe2 and Fe3, possess weaker hard-axis anisotropy (D = 8-10 cm-1, |E/D| = 0.06-0.21). These single-ion parameters were held constant in the fitting of DC magnetic data, which revealed ferromagnetic Fe1-Fe2 and Fe3-Fe4 interactions and antiferromagnetic Fe2-Fe3 coupling. The competition between super-exchange interactions and the large, noncollinear anisotropies at metal sites results in a weakly magnetic non-Kramers doublet ground state. This explains the SMM behavior displayed by both derivatives in the AC susceptibility data, with slow magnetic relaxation in 1Br being observable even in zero static field.
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Affiliation(s)
- Alessio Nicolini
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia & INSTM, I-41125 Modena, Italy. and Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, I-41125 Modena, Italy
| | - Marco Affronte
- Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, I-41125 Modena, Italy
| | - Daniel J SantaLucia
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
| | - Marco Borsari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia & INSTM, I-41125 Modena, Italy.
| | - Benjamin Cahier
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Matteo Caleffi
- Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, I-41125 Modena, Italy
| | - Antonio Ranieri
- Department of Life Sciences, University of Modena and Reggio Emilia, I-41125 Modena, Italy
| | - John F Berry
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
| | - Andrea Cornia
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia & INSTM, I-41125 Modena, Italy.
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Cornia A, Barra AL, Bulicanu V, Clérac R, Cortijo M, Hillard EA, Galavotti R, Lunghi A, Nicolini A, Rouzières M, Sorace L, Totti F. The Origin of Magnetic Anisotropy and Single-Molecule Magnet Behavior in Chromium(II)-Based Extended Metal Atom Chains. Inorg Chem 2020; 59:1763-1777. [PMID: 31967457 PMCID: PMC7901656 DOI: 10.1021/acs.inorgchem.9b02994] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chromium(II)-based extended metal atom chains have been the focus of considerable discussion regarding their symmetric versus unsymmetric structure and magnetism. We have now investigated four complexes of this class, namely, [Cr3(dpa)4X2] and [Cr5(tpda)4X2] with X = Cl- and SCN- [Hdpa = dipyridin-2-yl-amine; H2tpda = N2,N6-di(pyridin-2-yl)pyridine-2,6-diamine]. By dc/ac magnetic techniques and EPR spectroscopy, we found that all these complexes have easy-axis anisotropies of comparable magnitude in their S = 2 ground state (|D| = 1.5-1.8 cm-1) and behave as single-molecule magnets at low T. Ligand-field and DFT/CASSCF calculations were used to explain the similar magnetic properties of tri- versus pentachromium(II) strings, in spite of their different geometrical preferences and electronic structure. For both X ligands, the ground structure is unsymmetric in the pentachromium(II) species (i.e., with an alternation of long and short Cr-Cr distances) but is symmetric in their shorter congeners. Analysis of the electronic structure using quasi-restricted molecular orbitals (QROs) showed that the four unpaired electrons in Cr5 species are largely localized in four 3d-like QROs centered on the terminal, "isolated" Cr2+ ion. In Cr3 complexes, they occupy four nonbonding combinations of 3d-like orbitals centered only on the two terminal metals. In both cases, then, QRO eigenvalues closely mirror the 3d-level pattern of the terminal ions, whose coordination environment remains quite similar irrespective of chain length. We conclude that the extent of unpaired-electron delocalization has little impact on the magnetic anisotropy of these wire-like molecular species.
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Affiliation(s)
- Andrea Cornia
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , 41125 Modena , Italy
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses-CNRS , Université Grenoble-Alpes , 38042 Grenoble Cedex 9 , France
| | - Vladimir Bulicanu
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031 , 33600 Pessac , France
| | - Rodolphe Clérac
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031 , 33600 Pessac , France
| | - Miguel Cortijo
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031 , 33600 Pessac , France
| | - Elizabeth A Hillard
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031 , 33600 Pessac , France
| | - Rita Galavotti
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , 41125 Modena , Italy
| | - Alessandro Lunghi
- School of Physics and CRANN Institute , Trinity College Dublin , Dublin 2 , Ireland
| | - Alessio Nicolini
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , 41125 Modena , Italy.,Department of Physics, Informatics, and Mathematics , University of Modena and Reggio Emilia , 41125 Modena , Italy
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031 , 33600 Pessac , France
| | - Lorenzo Sorace
- Department of Chemistry "Ugo Schiff" , University of Florence & INSTM , 50019 Sesto Fiorentino (FI) , Italy
| | - Federico Totti
- Department of Chemistry "Ugo Schiff" , University of Florence & INSTM , 50019 Sesto Fiorentino (FI) , Italy
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Ou JH, Jin BY. Band Structures of Quasi-One-Dimensional Incommensurate Helical Systems: A Case Study of Infinite Chromium Extended Metal Atom Chain. J Phys Chem A 2018; 122:9199-9208. [PMID: 30444123 DOI: 10.1021/acs.jpca.8b07144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Extended metal atom chains (EMACs) are promising candidates for molecular wires but their band structures remain to be explored. As a quasi-one-dimensional (Q1D) system, the incommensurate helical nature of EMACs hinders such calculations. In this work, we resolved this issue via explicit implementation of helical symmetry. Moreover, the pattern of metal d bands was rationalized by a systematic investigation on a series of related Q1D helical systems. Two critical factors, helical ligand field and chemically asymmetric ligand field, are proposed and identified. We found that the symmetry and ligand fields of the system dominate the pattern of the metal d bands, instead of specific chemical composition of ligands. The presented method and rationale are applicable to not only EMACs but also related Q1D helical systems.
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Affiliation(s)
- Jen-Hao Ou
- Department of Chemistry , National Taiwan University , Taipei 10617 , Taiwan
| | - Bih-Yaw Jin
- Department of Chemistry , National Taiwan University , Taipei 10617 , Taiwan
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Otto S, Förster C, Wang C, Resch-Genger U, Heinze K. A Strongly Luminescent Chromium(III) Complex Acid. Chemistry 2018; 24:12555-12563. [DOI: 10.1002/chem.201802797] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/02/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Sven Otto
- Institute of Inorganic Chemistry and Analytical Chemistry; Johannes Gutenberg University of Mainz; Duesbergweg 10-14 55128 Mainz Germany
- Graduate School Materials Science in Mainz; Staudingerweg 9 55128 Mainz Germany
| | - Christoph Förster
- Institute of Inorganic Chemistry and Analytical Chemistry; Johannes Gutenberg University of Mainz; Duesbergweg 10-14 55128 Mainz Germany
| | - Cui Wang
- Division 1.2 Biophotonics; Federal Institute for Materials Research and Testing (BAM); Richard Willstätter-Straße 11 12489 Berlin Germany
- Institut für Chemie und Biochemie; Freie Universität Berlin; 14195 Berlin Germany
| | - Ute Resch-Genger
- Division 1.2 Biophotonics; Federal Institute for Materials Research and Testing (BAM); Richard Willstätter-Straße 11 12489 Berlin Germany
| | - Katja Heinze
- Institute of Inorganic Chemistry and Analytical Chemistry; Johannes Gutenberg University of Mainz; Duesbergweg 10-14 55128 Mainz Germany
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Nicolini A, Galavotti R, Barra AL, Borsari M, Caleffi M, Luo G, Novitchi G, Park K, Ranieri A, Rigamonti L, Roncaglia F, Train C, Cornia A. Filling the Gap in Extended Metal Atom Chains: Ferromagnetic Interactions in a Tetrairon(II) String Supported by Oligo-α-pyridylamido Ligands. Inorg Chem 2018; 57:5438-5448. [PMID: 29668273 DOI: 10.1021/acs.inorgchem.8b00405] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The stringlike complex [Fe4(tpda)3Cl2] (2; H2tpda = N2, N6-bis(pyridin-2-yl)pyridine-2,6-diamine) was obtained as the first homometallic extended metal atom chain based on iron(II) and oligo-α-pyridylamido ligands. The synthesis was performed under strictly anaerobic and anhydrous conditions using dimesityliron, [Fe2(Mes)4] (1; HMes = mesitylene), as both an iron source and a deprotonating agent for H2tpda. The four lined-up iron(II) ions in the structure of 2 (Fe···Fe = 2.94-2.99 Å, Fe···Fe···Fe = 171.7-168.8°) are wrapped by three doubly deprotonated twisted ligands, and the chain is capped at its termini by two chloride ions. The spectroscopic and electronic properties of 2 were investigated in dichloromethane by UV-vis-NIR absorption spectroscopy, 1H NMR spectroscopy, and cyclic voltammetry. The electrochemical measurements showed four fully resolved, quasi-reversible one-electron-redox processes, implying that 2 can adopt five oxidation states in a potential window of only 0.8 V. Direct current (dc) magnetic measurements indicate dominant ferromagnetic coupling at room temperature, although the ground state is only weakly magnetic. On the basis of density functional theory and angular overlap model calculations, this magnetic behavior was explained as being due to two pairs of ferromagnetically coupled iron(II) ions ( J = -21 cm-1 using JŜ i·Ŝ j convention) weakly antiferromagnetically coupled with each other. Alternating-current susceptibility data in the presence of a 2 kOe dc field and at frequencies up to 1.5 kHz revealed the onset of slow magnetic relaxation below 2.8 K, with the estimated energy barrier Ueff/ kB = 10.1(1.3) K.
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Affiliation(s)
- Alessio Nicolini
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy.,Department of Physics, Informatics and Mathematics , University of Modena and Reggio Emilia , I-41125 Modena , Italy
| | - Rita Galavotti
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses-CNRS , Université Grenoble-Alpes , F-38042 Grenoble Cedex 9 , France
| | - Marco Borsari
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy
| | - Matteo Caleffi
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy
| | - Guangpu Luo
- Department of Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Ghenadie Novitchi
- Laboratoire National des Champs Magnétiques Intenses-CNRS , Université Grenoble-Alpes , F-38042 Grenoble Cedex 9 , France
| | - Kyungwha Park
- Department of Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Antonio Ranieri
- Department of Life Sciences , University of Modena and Reggio Emilia , I-41125 Modena , Italy
| | - Luca Rigamonti
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy
| | - Fabrizio Roncaglia
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy
| | - Cyrille Train
- Laboratoire National des Champs Magnétiques Intenses-CNRS , Université Grenoble-Alpes , F-38042 Grenoble Cedex 9 , France
| | - Andrea Cornia
- Department of Chemical and Geological Sciences , University of Modena and Reggio Emilia & INSTM , I-41125 Modena , Italy
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