1
|
Song H, Jin C, Wang X, Xie J, Ma Y, Tang J, Li L. Tuning spin dynamics of binuclear Dy complexes using different nitroxide biradical derivatives. Dalton Trans 2024. [PMID: 38814577 DOI: 10.1039/d3dt04360f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
By employing nitronyl/imino nitroxide biradicals, three Ln-Zn complexes, namely, [Ln2Zn2(hfac)10(ImPhPyobis)2] (LnIII = Gd 1, Dy 2; hfac = hexafluoroacetylacetonate; ImPhPyobis = 5-(4-oxypyridinium-1-yl)-1,3-bis(1'-oxyl-4',4',5',5'-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene) and [Dy2Zn2(hfac)10(NITPhPyobis)2] 3 (NITPhPyobis = 5-(4-oxypyridinium-1-yl)-1,3-bis(1'-oxyl-3'-oxido-4',4',5',5'-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene), have been successfully prepared. The three complexes possess {Ln2O2} cores bridged by the oxygen atoms of the 4-oxypyridinium rings of the biradical ligands and one of the imino/nitronyl nitroxide groups of the biradical is coordinated to a ZnII ion, then producing a centrosymmetric tetranuclear six-spin structure. The studies of spin dynamics indicate that complexes 2 and 3 exhibit distinct magnetic relaxation behaviors at zero dc field: complex 2 presents single relaxation with an effective energy barrier (Ueff) of 69.8 K, while complex 3 exhibits double relaxation processes with Ueff values for the fast and slow relaxation being 15.8 K and 50.9 K, respectively. The observed different magnetic relaxation behaviors for the two Dy complexes could be mainly ascribed to the influence of the distinct nitroxide biradical derivatives.
Collapse
Affiliation(s)
- Hongwei Song
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Chaoyi Jin
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Xiaotong Wang
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Junfang Xie
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Yue Ma
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Licun Li
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
| |
Collapse
|
2
|
Wang F, Zhong ZB, Jia RX, Xing K, Cao R, Bai F, Duan PC. Three Oxidation States of Cobalt(I/II/III) Complexes by Thiaporphyrin. Inorg Chem 2024; 63:7233-7240. [PMID: 38588385 DOI: 10.1021/acs.inorgchem.3c04491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Reaction of tetraphenyl-21-thiaporphyrin (HSTPP) with cobalt salt yields a pentacoordinated high-spin 3/2 [CoIICl(STTP)] (1). Through ion exchange, a roughly square-planar-geometry low-spin 1/2 CoIISTTP(BArF24) (2) complex was isolated. These two paramagnetic precursors were examined by single X-ray diffraction, nuclear magnetic resonance, electron paramagnetic resonance, superconducting quantum interference device, and density functional theory calculations. These two allowed the development of one electron reduction and oxidation to give [CoI(STTP)] (3), [CoIII(STTP)Cl(CH3CN)](BF4) (4), and [CoIII(STTP)Cl2] (5). The products of the chemical redox reactions were isolated and fully characterized. In addition, the reactivity of [CoIICl(STTP)] (1) was examined by azide (N3), cyanate (OCN), and thiocyanate (SCN) and featured a preferential N-coordination to the cobalt metal.
Collapse
Affiliation(s)
- Fang Wang
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China
| | - Zi-Bin Zhong
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China
| | - Ri-Xin Jia
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China
| | - Kang Xing
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China
| | - Ronghui Cao
- College of Chemistry and Chemical Engineering, Luoyang Normal University, Henan Province Function-Oriented Porous Materials Key Laboratory, Luoyang 471934, China
| | - Feng Bai
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China
| | - Peng-Cheng Duan
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, Henan University, Kaifeng 475004, China
| |
Collapse
|
3
|
Keot N, Sarma M. Probing the dynamic behaviour and magnetic identification of seven coordinated Mn(II) complexes: a combined AIMD and multi-reference approach. Phys Chem Chem Phys 2023; 25:31165-31177. [PMID: 37953737 DOI: 10.1039/d3cp04072k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
We present an in-depth solution phase dynamics of rare seven coordinated pentagonal bipyramidal Mn(II) complexes, together with their binding affinity anticipated using ab initio molecular dynamics (AIMD) simulations and density functional theory (DFT). Moreover, the simulations at different temperatures (25 °C and 90 °C) interpret the rigidity and stability of the ligands with Mn(II) ions. An intuitive approach for modulating the easy plane magnetic anisotropy of the mononuclear Mn(II) complex has been revealed by this work. In this regard, we have performed an extensive theoretical study based on the ab initio CASSCF/NEVPT2 method, exhibiting the presence of an easy plane magnetic anisotropy with a positive value of axial zero-field splitting (ZFS) parameter D. The complex's magnetic properties and electronic relaxation reveal that the rhombic ZFS term (E) can be modulated as the symmetry around the Mn(II) ion varies. The magnitude of the D-value increased with a more symmetrical equatorial ligand as found in the order of [Mn(pydpa)(H2O)] > [Mn(cbda)(H2O)]- > [Mn(dpaaa)(H2O)]- > [Mn(dpasam)(H2O)]-. Furthermore, we found that substituting the equatorial oxygen atom with heavier S and Se-donor atoms switches the sign of magnetic anisotropy for the Mn(II) complexes. The magnitude of the D-value increased when the energy levels of the ground state (GS) and the first excited state (ES) decreased. The observed magneto-structural correlation reveals that shortening the distance of the axial water molecule (Mn-O(w)) increases the D-value by an order of magnitude for the symmetrical [Mn(pydpa)(H2O)] complex. Overall, the combined analysis of solution phase dynamics of Mn(II) complexes and their magnetic characterization opens up new avenues in coordination chemistry, molecular magnetism, spin-crossover materials, and catalysis.
Collapse
Affiliation(s)
- Niharika Keot
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam, 781039, India.
| | - Manabendra Sarma
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam, 781039, India.
| |
Collapse
|
4
|
Dey A, Ali J, Moorthy S, Gonzalez JF, Pointillart F, Singh SK, Chandrasekhar V. Field induced single ion magnet behavior in Co II complexes in a distorted square pyramidal geometry. Dalton Trans 2023; 52:14807-14821. [PMID: 37791680 DOI: 10.1039/d3dt01769a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
We report three CoII-based complexes with the general formula [CoII(L)(X)2] by changing the halide/pseudo-halide ions [X = NCSe (1SeCN); Cl (2Cl) and Br (3Br)]. The obtained τ5 and CShM values confirm a distorted square pyramidal geometry around the CoII ion in all these complexes. In these three complexes, the central CoII ion is situated above the basal plane of the square pyramidal geometry. The extent of distortion from the ideal SPY-5 geometry differs upon changing the coordinating halide/pseudo-halide ion in these complexes. This essentially results in the alteration of the anisotropic parameter D and hence impacts the magnetic properties in these complexes. This phenomenon has been corroborated with the aid of theoretical investigations. All these complexes display field-induced SIM behaviour with magnetic relaxation occurring through a combination of processes depending on the applied dc magnetic field values and dilution.
Collapse
Affiliation(s)
- Atanu Dey
- Department of Chemistry, Gandhi Institute of Technology and Management (GITAM), NH 207, Nagadenehalli, Doddaballapur Taluk, Bengaluru 561203, India.
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India.
| | - Junaid Ali
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India.
| | - Jessica Flores Gonzalez
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Fabrice Pointillart
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India.
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India.
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| |
Collapse
|
5
|
Wang M, Han Z, Gou X, Shi W, Zhang YQ, Cheng P. Alkyl Chains Modulated Magnetization Dynamics of Mononuclear Trigonal Prismatic Co II Complexes. Chemistry 2023; 29:e202301693. [PMID: 37498805 DOI: 10.1002/chem.202301693] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 07/29/2023]
Abstract
Four benzeneboron-capped mononuclear CoII complexes with different alkyl substitutions on the fourth position of phenylboronic acid were obtained. The CoII ions are all wrapped by the pocket-like ligands and located in trigonal prismatic coordination geometries. Alternating-current magnetic susceptibility measurements reveal that they show different magnetization dynamics, such as distinct relaxation rates at the same temperature, the faster QTM rates for the ethyl and propyl substituted complexes, as well as different relaxation processes. Magneto-structural correlation study reveals that the various deviations of coordination geometry of CoII ion, diverse crystal packings and possible different vibration modes of substituents caused by modifying alkyl chains are the key factors affecting the magnetization dynamics. This work demonstrates that the alkyl chains even locating far away from the metal center can have a large impact on the magnetic behavior of the CoII complex with a very rigid coordination geometry, offering a new perspective towards transition metal based single-molecule magnets.
Collapse
Affiliation(s)
- Mengmeng Wang
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Zongsu Han
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xiaoshuang Gou
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Wei Shi
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Yi-Quan Zhang
- School of Physical Science and Technology, Nanjing Normal University, Nanjing, 210023, P. R. China
| | - Peng Cheng
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300192, China
| |
Collapse
|
6
|
Kalita P, Ahmed N, Moorthy S, Béreau V, Bar AK, Kumar P, Nayak P, Sutter JP, Singh SK, Chandrasekhar V. Slow magnetic relaxation in a homoaxially phosphine oxide coordinated pentagonal bipyramidal Dy(III) complex. Dalton Trans 2023; 52:2804-2815. [PMID: 36752179 DOI: 10.1039/d2dt03789k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We report the synthesis of [(L)DyIII(Cy3PO)2]·[BPh4] (1-Dy) (where H2L = 2,6-diacetylpyridine bis-benzoylhydrazone and Cy = cyclohexyl) which crystallized in the triclinic, P1̄ space group. The local geometry around Dy(III) in 1-Dy was found to be pentagonal bipyramidal (pseudo-D5h). The AC magnetic susceptibility measurements performed on 1-Dy and on its diluted 1-Y(Dy) samples showed a typical single-molecule magnet signature revealed by the appearance of AC-frequency dependent out-of-phase susceptibility signals in the absence of a static magnetic field. The out-of-phase AC susceptibility signals were well resolved on the application of a small magnetic field (HDC = 500 Oe) and yielded an energy barrier for magnetization flipping of Ueff/kB = 50 K for the diluted derivative. The magnetic studies on 1-Dy and 1-Y(Dy) and data analysis further confirm that Raman and QTM under-barrier magnetic relaxations play a crucial role in lowering Ueff despite the almost axial nature of the Dy(III) ion in 1-Dy. We have rationalized these observations through detailed ab initio calculations performed on the X-ray crystal structure of 1-Dy.
Collapse
Affiliation(s)
- Pankaj Kalita
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500046, India.
| | - Naushad Ahmed
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500046, India.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, Telangana, India.
| | - Virginie Béreau
- Laboratoire de Chimie de Coordination du CNRS, Université de Toulouse, CNRS, Toulouse, France. .,Université de Toulouse, Institut Universitaire de Technologie Paul Sabatier-Département de Chimie, Av. Georges Pompidou, F-81104 Castres, France
| | - Arun Kumar Bar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 501507, India
| | - Pawan Kumar
- Department of Chemistry, IIT Kanpur, Kanpur 208016, India
| | - Prakash Nayak
- School of Chemical Sciences, National Institute of Science Education and Research, HBNI, Bhubaneswar 752050, India
| | - Jean-Pascal Sutter
- Laboratoire de Chimie de Coordination du CNRS, Université de Toulouse, CNRS, Toulouse, France.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, Telangana, India.
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500046, India. .,Department of Chemistry, IIT Kanpur, Kanpur 208016, India
| |
Collapse
|
7
|
Kumar Sahu P, Kharel R, Shome S, Goswami S, Konar S. Understanding the unceasing evolution of Co(II) based single-ion magnets. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
8
|
Comba P, Rajaraman G, Sarkar A, Velmurugan G. What controls the magnetic anisotropy in heptacoordinate high-spin cobalt(II) complexes? A theoretical perspective. Dalton Trans 2022; 51:5175-5183. [PMID: 35274660 DOI: 10.1039/d1dt03903b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The magnetic anisotropy of sixteen seven-coordinate high-spin CoII complexes with O, N, Cl and I donors was investigated with state-of-the-art ab initio CASSCF/NEVPT2 calculations and compared with experimental data. Based on the nature of the equatorial and axial ligands, which were found to tune the zero-field splitting, the complexes were classified into four groups. The experimental zero-field splitting parameters D which, for the various structures are in a range of +30 to +60 cm-1, as well as the g and E values are well reproduced. The investigation of the electronic structure shows that in these pentagonal bipyramidal complexes the donors and symmetry in the equatorial plane play an important role in the values of the axial zero-field splitting parameter D, and breaking of the horizontal plane of symmetry was found to enhance the magnitude of the D value. Although negative values of D are a desired condition for SIMs, many CoII based SIMs with positive zero-field splitting are fundamentally important to understand the nature of magnetic anisotropy, and seven coordinate CoII complexes with a large overall crystal field splitting might provide a way forward in this class of molecules.
Collapse
Affiliation(s)
- Peter Comba
- Heidelberg University, Institute of Inorganic Chemistry and Interdisciplinary Center for Scientific Computing, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| | - Arup Sarkar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| | - Gunasekaran Velmurugan
- Heidelberg University, Institute of Inorganic Chemistry and Interdisciplinary Center for Scientific Computing, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| |
Collapse
|
9
|
Kubono K, Kashiwagi Y, Tani K, Yokoi K. Crystal structure of (7-{[bis(pyridin-2-ylmethyl)amino-κ3
N,N′,N′′]methyl}-5-chloroquinolin-8-ol)dibromidozinc(II). Acta Crystallogr E Crystallogr Commun 2022; 78:326-329. [PMID: 35371540 PMCID: PMC8900503 DOI: 10.1107/s2056989022001530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/09/2022] [Indexed: 11/13/2022]
Abstract
In the title compound, the ZnII atom has a distorted square-pyramidal coordination environment. The molecular structure exhibits an intramolecular O—H⋯N hydrogen bond. In the crystal, the molecules are linked by intermolecular C—H⋯Br hydrogen bonds, generating ribbon structures. These ribbons are linked though intermolecular C—H⋯Br hydrogen bonds, forming a two-dimensional network sheet. In the title compound, [ZnBr2(C22H19ClN4O)], the ZnII atom adopts a distorted square-pyramidal coordination geometry, formed by two bromido ligands and three N atoms of the bis(pyridin-2-ylmethyl)amine moiety in the pentadentate ligand containing quinolinol. The ZnII atom is located well above the mean basal plane of the square-based pyramid. The apical position is occupied by a Br atom. The O and N atoms of the quinolinol moiety in the ligand are not coordinated to the ZnII atom. An intramolecular O—H⋯N hydrogen bond, generating an S(5) ring motif, stabilizes the molecular structure. In the crystal, the molecules are linked by intermolecular C—H⋯Br hydrogen bonds, generating ribbon structures containing alternating R22(22) and R22(14) rings. These ribbons are linked through an intermolecular C—H⋯Br hydrogen bond, forming a two-dimensional network sheet.
Collapse
|
10
|
Chen Y, Yang Q, Peng G, Zhang YQ, Ren XM. Influence of F-position and solvent on coordination geometry and single ion magnet behavior of Co(II) complexes. Dalton Trans 2021; 50:13830-13840. [PMID: 34522941 DOI: 10.1039/d1dt02148f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Three mononuclear Co(II) complexes with the compositions of [Co(L1)2] (1), [Co(L2)2(CH3CN)] (2) and [Co(L3)2] (3) (HL1 = 2-((E)-(2-fluorobenzylimino)methyl)-4,6-dibromophenol, HL2 = 2-((E)-(3-fluorobenzylimino)methyl)-4,6-dibromophenol and HL3 = 2-((E)-(4-fluorobenzylimino)methyl)-4,6-dibromophenol) were prepared and structurally determined. The changes in the F-positions in the ligands and solvents led to the formation of these products with various coordination geometries. Both complexes 1 and 3 are four-coordinated and their coordination geometries can be described as tetrahedron and seesaw, whereas complex 2 is five coordinated with a coordination configuration in between trigonal bipyramid and square pyramid. Static magnetic studies reveal that all these complexes exhibit considerable easy-axis magnetic anisotropy. The easy-axis magnetic anisotropy of 1 and 3 mainly derives from the first quartet excited state, whereas that of 2 primarily originates from the first, third and fourth quartet excited states established by theoretical calculations. All the resulting complexes display field-induced slow magnetic relaxation. Complex 3 represents the first Co(II) single ion magnet with a seesaw coordination geometry. Ab initio calculations predict that the magnetic anisotropy will enhance when the seesaw coordination geometry varies from distortion to regulation.
Collapse
Affiliation(s)
- Yue Chen
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
| | - Qi Yang
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
| | - Guo Peng
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China.
| | - Xiao-Ming Ren
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
| |
Collapse
|
11
|
Tiaouinine S, Flores Gonzalez J, Lefeuvre B, Guizouarn T, Cordier M, Dorcet V, Kaboub L, Cador O, Pointillart F. Spin Crossover and Field‐Induced Single‐Molecule Magnet Behaviour in Co(II) Complexes Based on Terpyridine with Tetrathiafulvalene Analogues. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100247] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Siham Tiaouinine
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
- Laboratory of Organic Materials and Heterochemistry University of Tebessa Rue de Constantine 12002 Tébessa Algeria
| | - Jessica Flores Gonzalez
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Bertrand Lefeuvre
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Thierry Guizouarn
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Marie Cordier
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Vincent Dorcet
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Lakehmici Kaboub
- Laboratory of Organic Materials and Heterochemistry University of Tebessa Rue de Constantine 12002 Tébessa Algeria
- Laboratory of Chemistry Molecular Engineering and Nanostructures University of Ferhat Abbas-Sétif 1 19000 Sétif Algeria
| | - Olivier Cador
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Fabrice Pointillart
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| |
Collapse
|
12
|
Kumar P, SantaLucia DJ, Kaniewska-Laskowska K, Lindeman SV, Ozarowski A, Krzystek J, Ozerov M, Telser J, Berry JF, Fiedler AT. Probing the Magnetic Anisotropy of Co(II) Complexes Featuring Redox-Active Ligands. Inorg Chem 2020; 59:16178-16193. [DOI: 10.1021/acs.inorgchem.0c01812] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Praveen Kumar
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Daniel J. SantaLucia
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Kinga Kaniewska-Laskowska
- Department of Inorganic Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk PL-80-233, Poland
| | - Sergey V. Lindeman
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - John F. Berry
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Adam T. Fiedler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| |
Collapse
|
13
|
Cui HH, Ding MM, Zhang XD, Lv W, Zhang YQ, Chen XT, Wang Z, Ouyang ZW, Xue ZL. Magnetic anisotropy in square pyramidal cobalt(II) complexes supported by a tetraazo macrocyclic ligand. Dalton Trans 2020; 49:14837-14846. [PMID: 33034595 DOI: 10.1039/d0dt01954b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two five-coordinate mononuclear Co(ii) complexes [Co(12-TMC)X][B(C6H5)4] (L = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane (12-TMC), X = Cl- (1), Br- (2)) have been studied by X-ray single crystallography, magnetic measurements, high-frequency and -field EPR (HF-EPR) spectroscopy and theoretical calculations. Both complexes have a distorted square pyramidal geometry with the Co(ii) ion lying above the basal plane constrained by the rigid tetradentate macrocyclic ligand. In contrast to the reported five-coordinate Co(ii) complex [Co(12-TMC)(NCO)][B(C6H5)4] (3) exhibiting easy-axis anisotropy, an easy-plane magnetic anisotropy was found for 1 and 2via the analyses of the direct-current magnetic data and HF-EPR spectroscopy. Frequency- and temperature-dependent alternating-current magnetic susceptibility measurements demonstrated that complexes 1 and 2 show slow magnetic relaxation at an applied dc field. Ab initio calculations were performed to reveal the impact of the terminal ligands on the nature of the magnetic anisotropies of this series of five-coordinate Co(ii) complexes.
Collapse
Affiliation(s)
- Hui-Hui Cui
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|