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Hales DP, Rajeshkumar T, Shiau AA, Rao G, Ouellette ET, Bergman RG, Britt RD, Maron L, Arnold J. Panoply of P: An Array of Rhenium-Phosphorus Complexes Generated from a Transition Metal Anion. Inorg Chem 2024; 63:11296-11310. [PMID: 38836624 DOI: 10.1021/acs.inorgchem.4c01085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
We expand upon the synthetic utility of anionic rhenium complex Na[(BDI)ReCp] (1, BDI = N,N'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate) to generate several rhenium-phosphorus complexes. Complex 1 reacts in a metathetical manner with chlorophosphines Ph2PCl, MeNHP-Cl, and OHP-Cl to generate XL-type phosphido complexes 2, 3, and 4, respectively (MeNHP-Cl = 2-chloro-1,3-dimethyl-1,3,2-diazaphospholidine; OHP-Cl = 2-chloro-1,3,2-dioxaphospholane). Crystallographic and computational investigations of phosphido triad 2, 3, and 4 reveal that increasing the electronegativity of the phosphorus substituent (C < N < O) results in a shortening and strengthening of the rhenium-phosphorus bond. Complex 1 reacts with iminophosphane Mes*NPCl (Mes* = 2,4,6-tritert-butylphenyl) to generate linear iminophosphanyl complex 5. In the presence of a suitable halide abstraction reagent, 1 reacts with the dichlorophosphine iPr2NPCl2 to afford cationic phosphinidene complex 6+. Complex 6+ may be reduced by one electron to form 6•, a rare example of a stable, paramagnetic phosphinidene complex. Spectroscopic and structural investigations, as well as computational analyses, are employed to elucidate the influence of the phosphorus substituent on the nature of the rhenium-phosphorus bond in 2 through 6. Furthermore, we examine several common analogies employed to understand metal phosphido, phosphinidene, and iminophosphanyl complexes.
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Affiliation(s)
- David P Hales
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Thayalan Rajeshkumar
- LPCNO, INSA Toulouse, Université de Toulouse, 135 Avenue de Rangueil, Toulouse 31077, France
| | - Angela A Shiau
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Guodong Rao
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Erik T Ouellette
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Robert G Bergman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - R David Britt
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Laurent Maron
- LPCNO, INSA Toulouse, Université de Toulouse, 135 Avenue de Rangueil, Toulouse 31077, France
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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2
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Fine Structure and the Huge Zero-Field Splitting in Ni 2+ Complexes. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248887. [PMID: 36558020 PMCID: PMC9784865 DOI: 10.3390/molecules27248887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
We perform a thorough study of the ground state magnetic properties of nickel-based 3d8 complexes. This includes an in-depth analysis of the contribution of the crystal field, spin exchange and spin-orbit interactions to the ground state magnetic properties. Of particular interest to the current investigation are the presence and occurrence of non-trivial zero-field splitting. The study focuses on the cases of Ni2+ ideal octahedral, trigonal bipyramidal, square planar and tetrahedral geometries. We provide results for the complete energy spectrum, the fine structure related to the ground state and the second set of excited states, low-field magnetic susceptibility and magnetization. In addition, we examine the zero-field fine structure in square pyramidal, trigonal pyramidal and trigonal planar complexes. The obtained results unequivocally show that a moderate or highly coordinated 3d8 complex can neither exhibit spin-orbit-driven large and giant magnetic anisotropy nor a huge zero-field splitting. Moreover, in the trigonal bipyramidal coordination, a fine structure associated to the ground state cannot result from the spin-orbit coupling alone.
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3
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Nain S, Khurana R, Ali ME. Harnessing Colossal Magnetic Anisotropy in Sandwiched 3d 2-Metallocenes. J Phys Chem A 2022; 126:2811-2817. [PMID: 35507013 DOI: 10.1021/acs.jpca.2c01605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Single-molecule magnets are gaining attention in recent years with the growing focus on achieving higher barriers of magnetization reversal. Metallocenes, owing to their unique sandwiched structure, assure themselves as plausible molecular systems for the development of novel single-molecule magnets (SMMs). Here in this work, we have explicitly investigated metallocenes of first-row transition elements, along with their one-electron-oxidized (cationic) and -reduced (anionic) analogues, for their magnetic anisotropies by adopting multireference ab initio calculations. Herein, we report a high magnetic anisotropy for 3d2 systems among all 3d-metallocenes.
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Affiliation(s)
- Sakshi Nain
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| | - Rishu Khurana
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
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4
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Olding A, Tang M, Ho CC, Fuller RO, Bissember AC. Rhenium-catalysed reactions in chemical synthesis: selected case studies. Dalton Trans 2022; 51:3004-3018. [DOI: 10.1039/d1dt04205j] [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
This Perspective presents and discusses a selection of examples that reinforce the enabling and distinctive reactivity provided by homogeneous rhenium catalysis in chemical synthesis. Specifically, the ability for lower oxidation...
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5
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Brechin EK, Singh M, Etcheverry-Berríos A, Vallejo J, Sanz S, Martínez-Lillo J, Nichol GS, Lusby P. Guest-induced magnetic exchange in paramagnetic [M 2L 4] 4+ coordination cages. Dalton Trans 2022; 51:8377-8381. [DOI: 10.1039/d2dt01385a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Paramagnetic complexes that show magnetically switchable properties show promise in a number of applications. A significantly underdeveloped approach is the use of metallocages, whose magnetic properties can be modulated through...
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6
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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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Khurana R, Gupta S, Ali ME. First-Principles Investigations of Magnetic Anisotropy and Spin-Crossover Behavior of Fe(III)-TBP Complexes. J Phys Chem A 2021; 125:2197-2207. [PMID: 33617261 DOI: 10.1021/acs.jpca.1c00022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With the ongoing effort to obtain mononuclear 3d-transition-metal complexes that manifest slow relaxation of magnetization and, hence, can behave as single-molecule magnets (SMMs), we have modeled 14 Fe(III) complexes based on an experimentally synthesized (PMe3)2FeCl3 complex [J. Am. Chem. Soc. 2017, 139 (46), 16474-16477], by varying the axial ligands with group XV elements (N, P, and As) and equatorial halide ligands from F, Cl, Br, and I. Out of these, nine complexes possess large zero field splitting (ZFS) parameter D in the range of -40 to -60 cm-1. The first-principles investigation of the ground-spin state applying density functional theory (DFT) and wave function-based multiconfigurations methods, e.g., SA-CASSCF/NEVPT2, are found to be quite consistent except for few delicate cases with near-degenerate spin states. In such cases, the hybrid B3LYP functional is found to be biased toward high-spin (HS) state. Altering the percentage of exact exchange admixed in the B3LYP functional leads to intermediate-spin (IS) ground state consistent with the multireference calculations. The origin of large zero field splitting (ZFS) in the Fe(III)-based trigonal bipyramidal (TBP) complexes is investigated. Furthermore, a number of complexes are identified with very small ΔGHS-ISadia. values indicating the possible spin-crossover phenomenon between the bistable spin states.
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Affiliation(s)
- Rishu Khurana
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Sameer Gupta
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
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8
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Sarkar A, Dey S, Rajaraman G. Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in Fe II , Co II , and Ni II Single-Ion Magnets. Chemistry 2020; 26:14036-14058. [PMID: 32729641 DOI: 10.1002/chem.202003211] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/22/2022]
Abstract
Since the last decade, the focus in the area of single-molecule magnets (SMMs) has been shifting constructively towards the development of single-ion magnets (SIMs) based on transition metals and lanthanides. Although ground-breaking results have been witnessed for DyIII -based SIMs, significant results have also been obtained for some mononuclear transition metal SIMs. Among others, studies based on CoII ion are very prominent as they often exhibit high magnetic anisotropy or zero-field splitting parameters and offer a large barrier height for magnetisation reversal. Although CoII possibly holds the record for having the largest number of zero-field SIMs known for any transition metal ion, controlling the magnetic anisotropy in these systems are is still a challenge. In addition to the modern spectroscopic techniques, theoretical studies, especially ab initio CASSCF/NEVPT2 approaches, have been used to uncover the electronic structure of various CoII SIMs. In this article, with some selected examples, the aim is to showcase how varying the coordination number from two to eight, and the geometry around the CoII centre alters the magnetic anisotropy. This offers some design principles for the experimentalists to target new generation SIMs based on the CoII ion. Additionally, some important FeII /FeIII and NiII complexes exhibiting large magnetic anisotropy and SIM properties are also discussed.
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Affiliation(s)
- Arup Sarkar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
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9
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Acharya J, Ahmed N, Flores Gonzalez J, Kumar P, Cador O, Singh SK, Pointillart F, Chandrasekhar V. Slow magnetic relaxation in a homo dinuclear Dy(iii) complex in a pentagonal bipyramidal geometry. Dalton Trans 2020; 49:13110-13122. [PMID: 32930277 DOI: 10.1039/d0dt02881a] [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]
Abstract
We hereby report a dinuclear Dy(iii) complex, [Dy(LH3)Cl2]2·2Et2O (1) (LH4 = 2,3-dihydroxybenzylidene)-2-(hydroxyimino)propanehydrazide where both the metal centres are in a pentagonal bipyramidal (PBP) geometry with the axial positions being occupied by negatively charged Cl- ions. The complex as well as it's 10% diluted analogue (110) do not show zero-field SMM behaviour. However, in the presence of small optimum dc fields the slow relaxation of magnetization was displayed. The effective energy barrier for 110 at 800 Oe of applied field was extracted as 83(17) K with τ0 = 2(4) × 10-12 s. Through a combined experimental and ab initio electronic structure calculations studies we have thoroughly analysed the role of the ligand field around the Dy(iii), present in pentagonal bipyramidal geometry, in contributing to the slow relaxation of magnetization.
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Affiliation(s)
- Joydev Acharya
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, India.
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10
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Mondal A, Wu S, Sato O, Konar S. Effect of Axial Ligands on Easy‐Axis Anisotropy and Field‐Induced Slow Magnetic Relaxation in Heptacoordinated Fe
II
Complexes. Chemistry 2020; 26:4780-4789. [DOI: 10.1002/chem.201905166] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Arpan Mondal
- Department of ChemistryIndian Institute of, Science Education and Research, Bhopal Bhopal By-pass Road, Bhauri Bhopal 462066 Madhya Pradesh India
| | - Shu‐Qi Wu
- Institute for Materials Chemistry and Engineering & IRCCSKyushu University 744 Motooka Nishi-ku 819-0395 Fukuoka Japan
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering & IRCCSKyushu University 744 Motooka Nishi-ku 819-0395 Fukuoka Japan
| | - Sanjit Konar
- Department of ChemistryIndian Institute of, Science Education and Research, Bhopal Bhopal By-pass Road, Bhauri Bhopal 462066 Madhya Pradesh India
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11
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Singh MK, Shukla P, Khatua M, Rajaraman G. A Design Criteria to Achieve Giant Ising-Type Anisotropy in Co II -Encapsulated Metallofullerenes. Chemistry 2019; 26:464-477. [PMID: 31506987 DOI: 10.1002/chem.201903618] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/05/2019] [Indexed: 11/10/2022]
Abstract
Discovery of permanent magnetisation in molecules just like in hard magnets decades ago led to the proposal of utilising these molecules for information storage devices and also as Q-bits in quantum computing. A significant breakthrough with a blocking temperature as high as 80 K has been recently reported for lanthanocene complexes. While enhancing the blocking temperature further remains one of the primary challenges, obtaining molecules that are suitable for the fabrication of the devices sets the bar very high in this area. Encouraged by the fact that our earlier predictions of potential single-molecule magnets (SMMs) in lanthanide-containing endohedral fullerenes have been verified, here we set out to undertake a comprehensive study on CoII -ion-encapsulated fullerene as potential SMMs. To study this class of molecules, we have utilised an array of theoretical methods ranging from density functional to ab initio CASSCF/NEVPT2 methods for obtaining reliable estimate of zero-field splitting parameters D and E. Additionally, we have also employed, for the first time a combination of molecular dynamics based on DFT methods coupled with CASSCF/NEVPT2 methods to seek the role of conformational isomers in the relaxation of magnetisation. Particularly, we have studied, Co@C28 , Co@C38 and Co@C48 cages and their isomers as potential target molecules that could yield substantial magnetic anisotropy. Our calculations categorically reveal a very large Ising anisotropy in this class of molecules, with Co@C48 cages predicted to yield D values as high as -127 cm-1 . Our calculations on the smaller cages reveal the free movement of CoII ion inside the cage, leading to the likely scenario of faster relaxation of magnetisation. However, larger fullerene cages were found to solve this issue. Further models with incorporating units such as {CoOZn}, {CoScZnN} inside larger fullerenes yield axial zero-field splitting values as high as -200 cm-1 with negligible E/D values. As these units represent a strong axiality coupled with a viable way to obtain air-stable low-coordinate CoII complexes, this opens up a new paradigm in the search of SMMs in this class of molecules.
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Affiliation(s)
- Mukesh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Pratima Shukla
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Munmun Khatua
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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12
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Hay MA, Sarkar A, Marriott KER, Wilson C, Rajaraman G, Murrie M. Investigation of the magnetic anisotropy in a series of trigonal bipyramidal Mn(ii) complexes. Dalton Trans 2019; 48:15480-15486. [PMID: 31282505 DOI: 10.1039/c9dt02187f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Understanding how the magnetic anisotropy in simple coordination complexes can be manipulated is instrumental to the development of single-molecule magnets (SMMs). Clear strategies can then be designed to control both the axial and transverse contributions to the magnetic anisotropy in such compounds, and allow them to reach their full potential. Here we show a strategy for boosting the magnetic anisotropy in a series of trigonal bipyramidal Mn(ii) complexes - [MnCl3(HDABCO)(DABCO)] (1), [MnCl3(MDABCO)2]·[ClO4] (2), and [MnCl3(H2O)(MDABCO)] (3). These have been successfully synthesised using the monodentate [DABCO] and [MDABCO]+ ligands. Through static (DC) magnetic measurements and detailed theoretical investigation using ab initio methods, the magnetic anisotropy of each system has been studied. The calculations reveal that the rhombic zero-field splitting (ZFS) term (E) can be tuned as the symmetry around the Mn(ii) ion is changed. Furthermore, an in silico investigation reveals a strategy to increase the axial ZFS parameter (D) of trigonal bipyramidal Mn(ii) by an order of magnitude.
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Affiliation(s)
- Moya A Hay
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Arup Sarkar
- Department of Chemistry, Institute of Technology Bombay, Powai, Mumbai, Maharashtra 400 076, India.
| | - Katie E R Marriott
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Claire Wilson
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Gopalan Rajaraman
- Department of Chemistry, Institute of Technology Bombay, Powai, Mumbai, Maharashtra 400 076, India.
| | - Mark Murrie
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
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13
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Hay MA, Sarkar A, Craig GA, Bhaskaran L, Nehrkorn J, Ozerov M, Marriott KER, Wilson C, Rajaraman G, Hill S, Murrie M. In-depth investigation of large axial magnetic anisotropy in monometallic 3d complexes using frequency domain magnetic resonance and ab initio methods: a study of trigonal bipyramidal Co(ii). Chem Sci 2019; 10:6354-6361. [PMID: 31341591 PMCID: PMC6601423 DOI: 10.1039/c9sc00987f] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/19/2019] [Indexed: 11/21/2022] Open
Abstract
The magnetic properties of 3d monometallic complexes can be tuned through geometric control, owing to their synthetic accessibility and relative structural simplicity. Monodentate ligands offer great potential for fine-tuning the coordination environment to engineer both the axial and rhombic zero-field splitting (ZFS) parameters. In [CoCl3(DABCO)(HDABCO)] (1), the trigonal bipyramidal Co(ii) centre has two bulky axial ligands and three equatorial chloride ligands. An in-depth experimental and theoretical study of 1 reveals a large easy-plane magnetic anisotropy (+ve D) with a negligible rhombic zero-field splitting (E) due to the strict axial symmetry imposed by the C 3 symmetric ligand and trigonal space group. The large easy-plane magnetic anisotropy (D = +44.5 cm-1) is directly deduced using high-field EPR and frequency-domain magnetic resonance (FDMR) studies. Ab initio calculations reveal a large positive contribution to the D term arising from ground state/excited state mixing of the 4E'' states at ∼4085 cm-1 and a minor contribution from the spin-flip transition as well. The nature of the slow relaxation in 1 is elucidated through analysis of the rates of relaxation of magnetisation, taking into account Raman and direct spin-lattice relaxation processes and Quantum Tunnelling of the Magnetisation (QTM). The terms relating to the direct process and QTM were found based on the fit of the field-dependence of τ at 2 K. Subsequently, these were used as fixed parameters in the fit of the temperature-dependence of τ to obtain the Raman terms. This experimental-theoretical investigation provides further insight into the power of FDMR and ab initio methods for the thorough investigation of magnetic anisotropy. Thus, these results contribute to design criteria for high magnetic anisotropy systems.
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Affiliation(s)
- Moya A Hay
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Arup Sarkar
- Department of Chemistry , Institute of Technology Bombay , Powai , Mumbai , Maharashtra 400 076 , India .
| | - Gavin A Craig
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Lakshmi Bhaskaran
- Department of Physics , Florida State University , Tallahassee , FL 32306 , USA .
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
| | - Joscha Nehrkorn
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36 , 45470 Mülheim an der Ruhr , Germany
| | - Mykhailo Ozerov
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
| | - Katie E R Marriott
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Claire Wilson
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Gopalan Rajaraman
- Department of Chemistry , Institute of Technology Bombay , Powai , Mumbai , Maharashtra 400 076 , India .
| | - Stephen Hill
- Department of Physics , Florida State University , Tallahassee , FL 32306 , USA .
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
| | - Mark Murrie
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
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14
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Kalofolias DA, Weselski M, Siczek M, Lis T, Tsipis AC, Tangoulis V, Milios CJ. Dinuclear and Mononuclear Rhenium Coordination Compounds upon Employment of a Schiff-Base Triol Ligand: Structural, Magnetic, and Computational Studies. Inorg Chem 2019; 58:8596-8606. [PMID: 31180213 DOI: 10.1021/acs.inorgchem.9b00886] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The 1:1 reaction of trans-[ReIIICl3(PPh3)2(MeCN)] with 2-(β-naphthalideneamino)-2-hydroxymethyl-1-propanol, H3L, in toluene gave the dinuclear complex [ReIII2Cl4(HL)(PPh3)]·2C7H8 (1·2C7H8), while the 1:2 reaction led to the formation of complex [ReIVCl2(HL)(PPh3)] (2). In both species, the Schiff-base ligand exists in its doubly deprotonated form, HL2-, forming chelate rings around the metallic centers. In addition, 1·2C7H8 displays a unique triple metal-to-metal bond between the two trivalent rhenium ions separated at a 2.229(1) Å bond distance, while in complex [ReIVCl2(HL)(PPh3)] (2) the two aromatic ligands, HL2- and PPh3, occupy axial positions, with the terminal Cl- ions in the trans position. Investigation of the magnetic properties revealed a Curie paramagnetic behavior ( S = 1/2) with a pronounced temperature independent paramagnetism (TIP) for 1·2C7H8 and 2. Both the geometry and the electronic structure of both compounds have been studied by means of density functional theory (DFT) calculations, confirming the triplet and doublet spin ground state of the complexes and furthermore establishing an electron-rich σ2π4δ1δ*1 bond order of 3 for 1·2C7H8. In addition, the absorption spectrum of 1·2C7H8 in CH2Cl2 was simulated by means of DFT calculations and is in excellent agreement with both the crystallographic and theoretical studies. Complex 1·2C7H8 is the first dinuclear rhenium complex with a triple metal-metal bond between trivalent rhenium centers.
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Affiliation(s)
| | - Marek Weselski
- Faculty of Chemistry , University of Wrocław , Joliot-Curie 14 , Wrocław 50-383 , Poland
| | - Milosz Siczek
- Faculty of Chemistry , University of Wrocław , Joliot-Curie 14 , Wrocław 50-383 , Poland
| | - Tadeusz Lis
- Faculty of Chemistry , University of Wrocław , Joliot-Curie 14 , Wrocław 50-383 , Poland
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15
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Whangbo MH, Xiang H, Koo HJ, Gordon EE, Whitten JL. Electronic and Structural Factors Controlling the Spin Orientations of Magnetic Ions. Inorg Chem 2019; 58:11854-11874. [PMID: 31247865 DOI: 10.1021/acs.inorgchem.9b00687] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Magnetic ions M in discrete molecules and extended solids form MLn complexes with their first-coordinate ligand atoms L. The spin moment of M in a complex MLn prefers a certain direction in coordinate space because of spin-orbit coupling (SOC). In this minireview, we examine the structural and electronic factors governing the preferred spin orientations. Elaborate experimental measurements and/or sophisticated computational efforts are required to find the preferred spin orientations of magnetic ions, largely because the energy scale of SOC is very small. The latter is also the very reason why one can readily predict the preferred spin orientation of M by analyzing the SOC-induced highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) interactions of the MLn complexes in terms of qualitative perturbation theory. The strength of this HOMO-LUMO interaction depends on the spin orientation, which is governed by the selection rules based on the minimum |ΔLz| value (i.e., the minimum difference in the magnetic quantum numbers) between the HOMO and LUMO. With the local z axis of MLn chosen as its n-fold rotational axis, the preferred spin orientation is parallel to the z axis (∥z) when |ΔLz| = 0 but perpendicular to the z axis (⊥z) when |ΔLz| = 1.
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Affiliation(s)
- Myung-Hwan Whangbo
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695-8204 , United States.,State Key Laboratory of Structural Chemistry , Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou 350002 , P. R. China.,State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , P. R. China
| | - Hongjun Xiang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics , Fudan University , Shanghai 200433 , P. R. China.,Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , P. R. China
| | - Hyun-Joo Koo
- Department of Chemistry and Research institute for Basic Sciences , Kyung Hee University , Seoul 02447 , Republic of Korea
| | - Elijah E Gordon
- Ames Laboratory, U.S. Department of Energy , Ames , Iowa 50011 , United States
| | - Jerry L Whitten
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695-8204 , United States
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16
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Koo HJ, Kasapbasi EE, Whitten JL, Whangbo MH. The Conceptual Dilemma of the One-Electron Picture in Describing the Uniaxial Magnetism at Linear Coordination Sites. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Hyun-Joo Koo
- Department of Chemistry and Research institute for Basic Sciences; Kyung Hee University; Seoul 02447 Republic of Korea
| | - Esra E. Kasapbasi
- Molecular Biology and Genetics; Halic University; Istanbul 34445 Turkey
| | - Jerry L. Whitten
- Department of Chemistry; North Carolina State University; Raleigh, NC 27695-8204 USA
| | - Myung-Hwan Whangbo
- Department of Chemistry; North Carolina State University; Raleigh, NC 27695-8204 USA
- State Key Laboratory of Structural Chemistry; Fujian Institute of Research on the Structure of Matter (FJIRSM); Chinese Academy of Sciences (CAS); Fuzhou 350002 China
- State Key Laboratory of Crystal Materials; Shandong University; Jinan 250100 China
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17
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Guo J, Sun J, Sun G, Sun Z, Li L. Construction and Magnetic Study of One‐Dimensional Lanthanide–Radical Chains Involving Pyridinone‐Substituted Nitronyl Nitroxide Radicals. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Jianni Guo
- Department of Chemistry Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule‐based Material Chemistry College of Chemistry Nankai University 300071 Tianjin China
| | - Juan Sun
- Department of Chemistry Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule‐based Material Chemistry College of Chemistry Nankai University 300071 Tianjin China
| | - Guifang Sun
- Department of Chemistry Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule‐based Material Chemistry College of Chemistry Nankai University 300071 Tianjin China
| | - Zan Sun
- Department of Chemistry Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule‐based Material Chemistry College of Chemistry Nankai University 300071 Tianjin China
| | - Licun Li
- Department of Chemistry Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule‐based Material Chemistry College of Chemistry Nankai University 300071 Tianjin China
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18
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Yamane T, Sugisaki K, Nakagawa T, Matsuoka H, Nishio T, Kinjyo S, Mori N, Yokoyama S, Kawashima C, Yokokura N, Sato K, Kanzaki Y, Shiomi D, Toyota K, Dolphin DH, Lin WC, McDowell CA, Tadokoro M, Takui T. Analyses of sizable ZFS and magnetic tensors of high spin metallocomplexes. Phys Chem Chem Phys 2018; 19:24769-24791. [PMID: 28868562 DOI: 10.1039/c7cp03850j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The fictitious spin-1/2 Hamiltonian approach is the putative method to analyze the fine-structure/hyperfine ESR spectra of high spin metallocomplexes having sizable zerofield splitting (ZFS), thus giving salient principal g-values far from around g = 2 without explicitly providing their ZFS parameters in most cases. Indeed, the significant departure of the g-values from g = 2 is indicative of the occurrence of their high spin states, but naturally they never agree with true g-values acquired by quantum chemical calculations such as sophisticated DFT or ab initio MO calculations. In this work, we propose facile approaches to determine the magnetic tensors of high spin metallocomplexes having sizable ZFS, instead of performing advanced high-field/high-frequency ESR spectroscopy. We have revisited analytical expressions for the relationship between effective g-values and true principal g-values for high spins. The useful analytical formulas for the geff-gtrue relationships are given for S's up to 7/2. The genuine Zeeman perturbation formalism gives the exact solutions for S = 3/2, and for higher S's it is much more accurate than the pseudo-Zeeman perturbation approach documented so far (A. Abragam and B. Bleaney, Electron Paramagnetic Resonance of Transition Metal Ions, 1970; J. R. Pilbrow, J. Magn. Reson., 1978, 31, 479; F. Trandafir et al., Appl. Magn. Reson., 2007, 31, 553; M. Fittipaldi et al., J. Phys. Chem. B, 2008, 112, 3859), in which the E(Sx2 - Sy2) term is putatively treated to the second order. To show the usefulness of the present approach, we exploit FeIII(Cl)OEP (S = 5/2) (OEP: 2,3,7,8,12,13,17,18-octaethylporphyrin) and CoIIOEP (S = 3/2) well magnetically diluted in the diamagnetic host crystal lattice of NiIIOEP. The advantage of single-crystal ESR spectroscopy lies in the fact that the molecular information on the principal axes of the magnetic tensors is crucial in comparing with reliable theoretical results. In high spin states of metallocomplexes with sizable ZFS in pseudo-octahedral symmetry, their fine-structure ESR transitions for the principal z-axis orientation appear in the lower field far from g = 2 at the X-band, disagreeing with the putative intuitive picture obtained using relevant ESR spectroscopy. A ReIII,IV dinuclear complex in a mixed valence state exemplifies the cases, whose fine-structure/hyperfine ESR spectra of the neat crystals have been analyzed in their principal-axis system. The DFT-based/ab initio MO calculations of the magnetic tensors for all the high spin entities in this work were carried out.
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Affiliation(s)
- Takeshi Yamane
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.
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19
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Coughtrie DJ, Giereth R, Kats D, Werner HJ, Köhn A. Embedded Multireference Coupled Cluster Theory. J Chem Theory Comput 2018; 14:693-709. [DOI: 10.1021/acs.jctc.7b01144] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- David J. Coughtrie
- Institute for Theoretical
Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Robin Giereth
- Institute for Theoretical
Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Daniel Kats
- Institute for Theoretical
Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Hans-Joachim Werner
- Institute for Theoretical
Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Andreas Köhn
- Institute for Theoretical
Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
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20
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Syntheses, crystal structures and magnetic properties of sandglass DyIII9 and irregular tetrahedron DyIII4 complexes. Polyhedron 2018. [DOI: 10.1016/j.poly.2017.11.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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21
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Sarkar A, Velmurugan G, Rajeshkumar T, Rajaraman G. Deciphering the origin of invariance in magnetic anisotropy in {FeIIS4} complexes: a theoretical perspective. Dalton Trans 2018; 47:9980-9984. [DOI: 10.1039/c8dt02145g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
By employing the state-of-the-art ab initio calculations, we have probed the origin of invariance in ZFS parameters in {FeIIS4} complexes.
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Affiliation(s)
- Arup Sarkar
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai
- India
| | | | | | - Gopalan Rajaraman
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai
- India
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22
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Singh SK, Vignesh KR, Archana V, Rajaraman G. Theoretical insights into the origin of magnetic exchange and magnetic anisotropy in {Re(IV)-M(II)} (M = Mn, Fe, Co, Ni and Cu) single chain magnets. Dalton Trans 2017; 45:8201-14. [PMID: 27096553 DOI: 10.1039/c5dt04928h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional calculations have been performed on a series of {Re(IV)-M(II)} (M = Mn(), Fe(), Co(), Ni(), Cu()) complexes to compute the magnetic exchange interaction between the Re(IV) and M(II) ions, and understand the mechanism of magnetic coupling in this series. DFT calculations yield J values of -5.54 cm(-1), +0.44 cm(-1), +10.5 cm(-1), +4.54 cm(-1) and +19 cm(-1) for complexes respectively, and these estimates are in general agreement with the experimental reports. Using molecular orbital (MO) and overlap integral analysis, we have established a mechanism of coupling for a {3d-5d} pair and the proposed mechanism rationalises both the sign and the magnitude of J values observed in this series. Our proposed mechanism of coupling has five contributing factors: (i) (Re)dyz-dyz(3d) overlap, (ii) (Re)dxz-dxz(3d) overlap, (iii) (Re)dxy-dxy(3d) overlap, (iv) (Re)eg-t2g(3d) overlaps and (v) (Re)eg-eg(3d) overlaps. Here, the first two terms are found to contribute to the antiferromagnetic part of the exchange, while the other three contribute to the ferromagnetic part. The last two terms correspond to the cross-interactions and also contribute to the ferromagnetic part of the exchange. A record high ferromagnetic J value observed for the {Re(IV)-Cu(II)} pair in complex is found to be due to a significant cross interaction between the dz(2) orbital of the Re(IV) ion and the dx(2)-y(2) orbital of the Cu(ii) ion. Magneto-structural correlations are developed for Re-C and M-N bond lengths and Re-C-N and M-N-C bond angles. Among the developed correlations, the M-N-C bond angle is found to be the most sensitive parameter which influences the sign and strength of J values in this series. The J values are found to be more positive (or less negative) as the angle increases, indicating stronger ferromagnetic coupling at linear M-N-C angles. Apart from the magnetic exchange interaction, we have also estimated the magnetic anisotropy of [ReCl4(CN)2](2-) and [(DMF)4(CN)M(II)(CN)] (M(II)-Fe(II), Co(II) and Ni(II)) units using the state-of-the-art ab initio CASSCF/PT2/RASSI-SO/SINGLE_ANISO approach. The calculated D and E values for these building units are found to be in agreement with the available experimental results. Particularly a large positive D computed for the [ReCl4(CN)2](2-) unit was found to arise from dxz/dyz → dxy excitations corresponding to the low-lying doublet states. Similarly, a very large positive D value computed for Fe(II) and Co(II) units are also rationalised based on the corresponding ground state electronic configurations computed. The non-collinearity of the Re(IV) ion and the M(II) ion axial anisotropy (DZZ) axis are found to diminish the anisotropy of the building unit, leading to the observation of moderate relaxation barriers for these molecules.
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Affiliation(s)
- Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Kuduva R Vignesh
- IITB-Monash Research Academy, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Velloth Archana
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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23
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Aramburu JA, García-Fernández P, García-Lastra JM, Moreno M. Large Differences in the Optical Spectrum Associated with the Same Complex: The Effect of the Anisotropy of the Embedding Lattice. Inorg Chem 2017; 56:8944-8953. [PMID: 28696706 DOI: 10.1021/acs.inorgchem.7b00932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transition-metal complexes with a well-defined geometry are usually considered to display almost the same properties independently of the system where they are embedded. Here we show that the above statement is not true depending on the anisotropy of the host lattice, which is revealed in the form of the electric field created by the rest of lattice ions over the complex. To illustrate this concept we analyze the origin of the surprisingly large differences in the d-d optical transitions of two systems containing square-planar CuF42- complexes, CaCuF4, and center II in Cu2+-doped Ba2ZnF6, even though the Cu2+-F-distance difference is just found to be 1%. Using a minimalist first-principles model we show that the different morphology of the host lattices creates an anisotropic field that red-shifts the in vacuo complex transitions to the 1.25-1.70 eV range in CaCuF4, while it blue-shifts them to the 1.70-3.0 eV region in Ba2ZnF6:Cu2+. This particular example shows how the lattice anisotropy strongly alters the optical properties of a given transition-metal complex. This knowledge opens a new path to tune the spectra of this large family of systems.
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Affiliation(s)
- José Antonio Aramburu
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria , Avenida de los Castros s/n, 39005 Santander, Spain
| | - Pablo García-Fernández
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria , Avenida de los Castros s/n, 39005 Santander, Spain
| | - Juan María García-Lastra
- Department of Energy Conversion and Storage, Technical University of Denmark , Fysikvej 309, 2800 Kgs, Lyngby, Denmark
| | - Miguel Moreno
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria , Avenida de los Castros s/n, 39005 Santander, Spain
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24
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[OsF6
]
x
−
: Molecular Models for Spin-Orbit Entangled Phenomena. Chemistry 2017; 23:11244-11248. [DOI: 10.1002/chem.201702894] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Indexed: 11/07/2022]
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25
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Pedersen AH, Geoghegan BL, Nichol GS, Lupton DW, Murray KS, Martínez-Lillo J, Gass IA, Brechin EK. Hexahalorhenate(iv) salts of metal oxazolidine nitroxides. Dalton Trans 2017; 46:5250-5259. [PMID: 28374882 DOI: 10.1039/c7dt00752c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Eight coordination compounds of formulae [FeII(L˙)2][ReIVCl6] (1a), [FeII(L˙)2][ReIVBr6] (1b), [CoII(L˙)2][ReIVCl6]·CH3CN (2a), [CoII(L˙)2][ReIVBr6] (2b), [NiII(L˙)(CH3CN)3][ReIVCl6]·CH3CN (3a), [NiII(L˙)(CH3CN)3][ReIVBr6]·3CH3CN (3b), [CuII(L˙)2][ReIVCl6] (4a) and [CuII(L˙)2][ReIVBr6] (4b), where L˙ is the aminoxyl radical chelating ligand, 4,4'-dimethyl-2,2'-di(2-pyridyl)oxazolidine-N-oxide, have been synthesised. Structural and magnetic studies reveal metal-radical intramolecular antiferromagnetic interactions in the [MII(L˙)2]2+ cations in the iron, cobalt and copper based compounds (1a, 1b, 2a, 2b, 4a and 4b) with the central metal ion low-spin in the case of iron (1a and 1b) and a gradual, cobalt based, spin-crossover transition present in 2a and 2b. The nickel based compounds, 3a and 3b, were analysed in the dried form (3a(dried) and 3b(dried)) and directly in acetonitrile (3a(solvated) and 3b(solvated)). Microanalysis and IR spectroscopy on 3a(dried) and 3b(dried) suggest that the dried samples are best formulated as [NiII(L˙)(H2O)3][ReIVX6], where X = Cl (3a(dried)) and Br (3b(dried)). All forms of 3a and 3b exhibit cationic metal-radical ferromagnetic interactions resulting in S = 3/2 ground states. In addition, 3a(dried) exhibits spin-canting behaviour with an ordering temperature of 2.7 K, an open hysteresis loop with a coercive field Hc = 580 Oe, and a remanent magnetisation Mr = 0.21μB, resulting in a canting angle of ∼1.8°. In contrast, 3b(dried) shows no spin-canting behaviour; a maximum in χMvs. T at T = 3 K suggesting long-range antiferromagnetic ordering. 3a(solvated) and 3b(solvated) show no indication of long-range magnetic ordering, unlike 4a and 4b where anomalies are evident in the low-temperature magnetic susceptibility measurements.
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Affiliation(s)
- Anders H Pedersen
- EaStCHEM School of Chemistry, The University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, Scotland, UK.
| | - Blaise L Geoghegan
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK.
| | - Gary S Nichol
- EaStCHEM School of Chemistry, The University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, Scotland, UK.
| | - David W Lupton
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Keith S Murray
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - José Martínez-Lillo
- Departament de Química Inorgànica/Instituto de Ciencia Molecular (ICMol), Universitat de València, C/Catedrático José Beltrán 2, 46980, Paterna (València), Spain.
| | - Ian A Gass
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK.
| | - Euan K Brechin
- EaStCHEM School of Chemistry, The University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, Scotland, UK.
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26
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Chowdhury SR, Mishra S. Heavy ligand atom induced large magnetic anisotropy in Mn(ii) complexes. Phys Chem Chem Phys 2017. [DOI: 10.1039/c7cp02957h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the search for single molecule magnets, metal ions are considered pivotal towards achieving large magnetic anisotropy barriers.
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Affiliation(s)
| | - Sabyashachi Mishra
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur
- India
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27
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Pedersen AH, Julve M, Martínez-Lillo J, Cano J, Brechin EK. Magneto-structural correlations in dirhenium(iv) complexes possessing magnetic pathways with even or odd numbers of atoms. Dalton Trans 2017; 46:11890-11897. [DOI: 10.1039/c7dt02612a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spin-polarization enforces either ferro- or antiferromagnetic exchange interactions between ReIV ions with odd or even numbers of intervening atoms.
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Affiliation(s)
- Anders H. Pedersen
- EaStCHEM School of Chemistry
- The University of Edinburgh
- EH9 3FJ Edinburgh
- UK
| | - Miguel Julve
- Departament de Química Inorgànica/Instituto de Ciencia Molecular (ICMol)
- Universitat de València
- Paterna
- Spain
| | - José Martínez-Lillo
- Departament de Química Inorgànica/Instituto de Ciencia Molecular (ICMol)
- Universitat de València
- Paterna
- Spain
| | - Joan Cano
- Departament de Química Inorgànica/Instituto de Ciencia Molecular (ICMol)
- Universitat de València
- Paterna
- Spain
| | - Euan K. Brechin
- EaStCHEM School of Chemistry
- The University of Edinburgh
- EH9 3FJ Edinburgh
- UK
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28
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Pressure induced enhancement of the magnetic ordering temperature in rhenium(IV) monomers. Nat Commun 2016; 7:13870. [PMID: 28000676 PMCID: PMC5187583 DOI: 10.1038/ncomms13870] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/07/2016] [Indexed: 01/17/2023] Open
Abstract
Materials that demonstrate long-range magnetic order are synonymous with information storage and the electronics industry, with the phenomenon commonly associated with metals, metal alloys or metal oxides and sulfides. A lesser known family of magnetically ordered complexes are the monometallic compounds of highly anisotropic d-block transition metals; the ‘transformation' from isolated zero-dimensional molecule to ordered, spin-canted, three-dimensional lattice being the result of through-space interactions arising from the combination of large magnetic anisotropy and spin-delocalization from metal to ligand which induces important intermolecular contacts. Here we report the effect of pressure on two such mononuclear rhenium(IV) compounds that exhibit long-range magnetic order under ambient conditions via a spin canting mechanism, with Tc controlled by the strength of the intermolecular interactions. As these are determined by intermolecular distance, ‘squeezing' the molecules closer together generates remarkable enhancements in ordering temperatures, with a linear dependence of Tc with pressure. Materials that demonstrate long-range magnetic order are synonymous with information storage. Here, the authors report the effect of pressure on two mononuclear rhenium compounds that exhibit long-range magnetic order under ambient conditions via a spin canting mechanism, where Tc is proportional to pressure.
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Bhattacharya D, Shil S, Misra A, Bytautas L, Klein DJ. Toward Molecular Magnets of Organic Origin via Anion−π Interaction Involving m-Aminyl Diradical: A Theoretical Study. J Phys Chem A 2016; 120:9117-9130. [DOI: 10.1021/acs.jpca.6b09666] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Debojit Bhattacharya
- Department of Marine Sciences, Texas A&M University at Galveston, Galveston, Texas 77553, United States
| | - Suranjan Shil
- Center
for Atomic Scale Materials Design, Department of Physics, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Anirban Misra
- Department
of Chemistry, University of North Bengal, Darjeeling, PIN. 734013, West Bengal, India
| | - Laimutis Bytautas
- Department
of Chemistry, Galveston College, 4015 Avenue Q, Galveston, Texas 77550, United States
| | - Douglas J. Klein
- Department of Marine Sciences, Texas A&M University at Galveston, Galveston, Texas 77553, United States
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30
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Feng X, Liu JL, Pedersen KS, Nehrkorn J, Schnegg A, Holldack K, Bendix J, Sigrist M, Mutka H, Samohvalov D, Aguilà D, Tong ML, Long JR, Clérac R. Multifaceted magnetization dynamics in the mononuclear complex [ReIVCl4(CN)2]2−. Chem Commun (Camb) 2016; 52:12905-12908. [DOI: 10.1039/c6cc05473k] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Slow magnetization dynamics in [ReIVCl4(CN)2]2−occursviamultiple intricate relaxation processes.
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Affiliation(s)
- Xiaowen Feng
- Department of Chemistry
- University of California Berkeley
- USA
| | - Jun-Liang Liu
- MOE Key Lab of Bioinorganic and Synthetic Chemistry
- School of Chemistry
- Sun Yat-Sen University
- Guangzhou 510275
- P. R. China
| | | | - Joscha Nehrkorn
- Berlin Joint EPR Laboratory
- Institut für Nanospektroskopie
- Helmholtz-Zentrum für Materialien und Energie
- 12489 Berlin
- Germany
| | - Alexander Schnegg
- Berlin Joint EPR Laboratory
- Institut für Nanospektroskopie
- Helmholtz-Zentrum für Materialien und Energie
- 12489 Berlin
- Germany
| | - Karsten Holldack
- Helmholtz-Zentrum für Materialien und Energie
- Inst. f. Methoden und Instrumente der Forschung mit Synchrotronstrahlung
- 12489 Berlin
- Germany
| | - Jesper Bendix
- Department of Chemistry
- University of Copenhagen
- DK-2100 Copenhagen
- Denmark
| | - Marc Sigrist
- Institut Laue-Langevin
- 38042 Grenoble Cedex 9
- France
- Institute of Chemistry
- Academia Sinica
| | - Hannu Mutka
- Institut Laue-Langevin
- 38042 Grenoble Cedex 9
- France
| | | | | | - Ming-Liang Tong
- MOE Key Lab of Bioinorganic and Synthetic Chemistry
- School of Chemistry
- Sun Yat-Sen University
- Guangzhou 510275
- P. R. China
| | - Jeffrey R. Long
- Department of Chemistry
- University of California Berkeley
- USA
- Materials Sciences Division
- Lawrence Berkeley National Laboratory
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31
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Zhang J, Zhang H, Chen Y, Zhang X, Li Y, Liu W, Dong Y. A series of dinuclear lanthanide complexes with slow magnetic relaxation for Dy2 and Ho2. Dalton Trans 2016; 45:16463-16470. [DOI: 10.1039/c6dt02962k] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Seven dinuclear complexes [Ln2L2(C2H5OH)2(NO3)2]·0.5py were prepared and characterized; complex 4 exhibits SMM behavior with a Ueff value of 66.7 K.
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Affiliation(s)
- Jin Zhang
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Haifeng Zhang
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Yanmei Chen
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Xiangfei Zhang
- Key Laboratory of Salt Lake Resources and Chemistry
- Qinghai Institute of Salt Lakes
- Chinese Academy of Sciences
- Xining 810008
- P. R. China
| | - Yahong Li
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Wei Liu
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Yaping Dong
- Key Laboratory of Salt Lake Resources and Chemistry
- Qinghai Institute of Salt Lakes
- Chinese Academy of Sciences
- Xining 810008
- P. R. China
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