51
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Zang S, Ren X, Su Y, Song Y, Tong W, Ni Z, Zhao H, Gao S, Meng Q. Observation of Magnetic Bistability in Polymorphs of the [Ni(dmit)2]− Complexes. Inorg Chem 2009; 48:9623-30. [DOI: 10.1021/ic900090e] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shuangquan Zang
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Xiaoming Ren
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Yang Su
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - You Song
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Wenjun Tong
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Zhaoping Ni
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Hanhua Zhao
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012
| | - Song Gao
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Qingjin Meng
- State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
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52
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Syntheses, molecular structures and magnetic properties of two hybrid organic–inorganic salts of bis(maleonitriledithiolato)copper(II) and substituted benzyl-4-dimethylaminopyridinium cations. TRANSIT METAL CHEM 2009. [DOI: 10.1007/s11243-009-9260-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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53
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Huang Q, Chen X, Tian J, Zuo HR, Zhou JR, Yang LM, Ni CL, Hu XL, Meng QJ. Two new ion-pair complexes containing derivatives of substituted benzyl isoquinolinium and bis(maleonitriledithiolato)nickelate monoanion: 3D crystal structures, magnetic properties and theoretical analyses. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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54
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Zuo HR, Wu LX, Huang Q, Chen X, Zhou JR, Yang LM, Ni CL, Hu XL. Synthesis, crystal structure and magnetic characterization of two new ion-pair complexes containing bis(maleonitriledithiolate)nickelate anion and substituted benzylpyridinium cation. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.04.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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55
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Ni CL, Huang Q, Zuo HR, Hou Y, Mang QJ. Syntheses, crystal structures, magnetic properties and theoretical analysis of two new molecular solids based on Ni(mnt) − 2. J COORD CHEM 2009. [DOI: 10.1080/00958970802617585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Chun-Lin Ni
- a Department of Applied Chemistry, College of Science , Centre of Inorganic Functional Materials, South China Agricultural University , Guangzhou , PRC
| | - Qian Huang
- a Department of Applied Chemistry, College of Science , Centre of Inorganic Functional Materials, South China Agricultural University , Guangzhou , PRC
| | - Hong-Rong Zuo
- a Department of Applied Chemistry, College of Science , Centre of Inorganic Functional Materials, South China Agricultural University , Guangzhou , PRC
| | - Yong Hou
- a Department of Applied Chemistry, College of Science , Centre of Inorganic Functional Materials, South China Agricultural University , Guangzhou , PRC
| | - Qing-Jin Mang
- b State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University , Nanjing , PRC
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56
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Huang Q, Liu JF, Zuo HR, Zhou JR, Hou Y, Ni CL, Meng QJ. 3D network structure and spin gap behavior in two new molecular magnets based on bis(maleonitriledithiolato)nickelate monoanion. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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57
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Zhang H, Zhou Q, Hu F, Xu H, Chang G. 1-(2-Fluorobenzylideneamino)pyridinium bis(1,2-dicyanoethene-1,2-dithiolato)nickelate(II). Acta Crystallogr Sect E Struct Rep Online 2009; 65:m599. [PMID: 21583820 PMCID: PMC2977634 DOI: 10.1107/s1600536809015360] [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: 04/14/2009] [Accepted: 04/24/2009] [Indexed: 12/04/2022]
Abstract
In the title complex, (C12H10FN2)2[Ni(C4N2S2)2], the anion lies on an inversion center with the NiII ion coordinated by four S atoms in a slightly distorted square-planar environment. In the unique cation, the dihedral angle between the benzene and pyridine rings is 7.1 (2) Å.
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58
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Tian ZF, Duan HB, Zhou H, Ren XM, Zhang H, Meng QJ. An intriguing NO2⋯π and CN⋯π interactions in [1-(4′-nitrobenzyl)pyrazinium][Ni(mnt)2]: Crystal structure, magnetic property and DFT calculation. INORG CHEM COMMUN 2009. [DOI: 10.1016/j.inoche.2008.11.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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59
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Neves AIS, Santos IC, Belo D, Almeida M. Cation and ligand roles in the coordination of FeIII bisdithiolene complexes; the crystal structures of (BrBzPy)2[Fe(qdt)2]2 and [Fe(α-tpdt)2]22− salts. CrystEngComm 2009. [DOI: 10.1039/b813242a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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60
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Syntheses, structures, and magnetic properties of two new molecular magnets containing Ni(mnt)2 monoanion and substituted 4-dimethylaminopyridinium. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.03.069] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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61
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Ion-pair charge transfer complexes with M…H-bonding interactions: Syntheses, crystal structures, electronic spectra and DFT calculations. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2008.07.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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62
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Rabaça S, Belo D, Cláudia Cerdeira A, Isabel Godinho Dias S, Berkemeier Castelo Branco M, Cristina Jesus Pereira L, Cordeiro Santos I, Fourmigué M, Almeida M. Crystal structure of (RBzPy)n[Ni(4-pedt)2] salts engineering by pyridine ring arrangements. CrystEngComm 2009. [DOI: 10.1039/b906594f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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63
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Unusual spin gap transition observed in two new molecular magnets based on [Ni(mnt)2]− monoanion (mnt2−=maleonitriledithiolate). J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2008.10.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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64
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Yu SS, Xian H, Tian ZF. Bis[1-(2,6-dichlorobenzyl)-3-methylpyrazin-1-ium] bis(maleonitriledithiolato)nickelate(II). Acta Crystallogr Sect E Struct Rep Online 2008; 64:m1444. [PMID: 21580883 PMCID: PMC2959589 DOI: 10.1107/s1600536808034776] [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: 10/14/2008] [Accepted: 10/24/2008] [Indexed: 11/10/2022]
Abstract
In the crystal structure of the title compound, (C12H11Cl2N2)2[Ni(C4N2S2)2], the NiII complex dianion is located on an inversion centre. The NiII atom is coordinated by four S atoms in a square-planar geometry. In the cation, the dihedral angle between the benzene and pyrazine rings is 85.2 (2)°.
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65
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Four novel ion-pair compounds consisting of 7,7,8,8-tetracyanoquinodimethane (TCNQ) radical: Syntheses, crystal structures and properties. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2008.02.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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66
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Ren X, Sui Y, Liu G, Xie J. Observation of intermolecular charge transfer in a quasi-one-dimensional molecular alloy system. J Phys Chem A 2008; 112:8009-14. [PMID: 18693711 DOI: 10.1021/jp8009194] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
X-band single-crystal electron paramagnetic resonance (EPR) studies of the molecular alloy [NO 2BzPy][Au 0.57Ni 0.43(mnt) 2] are presented in this paper. At room temperature, EPR spectra show both intense resonance signals (main signals) and weak satellite quartet lines. The characteristics of both intense and weak EPR signals depend on the magnetic field orientation. The main signals arise from two magnetically nonequivalent [Ni(mnt) 2] (-) anions, and their corresponding principal values of the g tensor are ( g x ') 1 = 2.04653, ( g y ') 1 = 2.00096, and ( g z ') 1 = 2.15319 and ( g x ') 2 = 2.04520, ( g y ') 2 = 1.99734, and ( g z ') 2 = 2.15361, respectively. The weak satellite lines, whose patterns strongly depend on the magnetic field direction, can be attributed to the hyperfine coupling of the electron spin with the (197)Au nucleus of the [Au(mnt) 2] (-) species. Density functional theory calculations for the spin and charge distributions of the dimer {[Ni(mnt) 2][Au(mnt) 2]} (2-) indicate that the hyperfine interaction of the electron spin with the (197)Au nuclear spins is caused, in part, by the charge transfer between the [Ni(mnt) 2] (-) and the [Au(mnt) 2] (-) species.
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Affiliation(s)
- Xiaoming Ren
- College of Science, Nanjing University of Technology, People's Republic of China.
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67
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Zuo H, Huang Q, Hou Y, Ni C, Hu X. The Spin Gap Transition around 180 K Observed in a New Molecular Magnet based on the [Ni(mnt) 2] -Monoanion and Substituted Benzylpyridinium. Z Anorg Allg Chem 2008. [DOI: 10.1002/zaac.200800200] [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]
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68
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Hou Y, Zhou J, Liu X, Yu L, Ni C. Syntheses, crystal structures, and properties of two salts based on Ni(mnt)2 (mnt2− = maleonitriledithiolate) anion and substituted triphenylphosphonium cation. TRANSIT METAL CHEM 2008. [DOI: 10.1007/s11243-008-9054-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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69
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Bian J, Chang Y, Zhang J. Theoretical Studies on the Magnetic Bistability of Dinickel Complex Tuned by Azide. J Phys Chem A 2008; 112:3186-91. [DOI: 10.1021/jp711121z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jiangyu Bian
- Faculty of Chemistry, Northeast Normal University, Changchun, 130024, China
| | - Yingfei Chang
- Faculty of Chemistry, Northeast Normal University, Changchun, 130024, China
| | - Jingping Zhang
- Faculty of Chemistry, Northeast Normal University, Changchun, 130024, China
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70
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Liu GX, Xu H, Ren XM, Sun WY. A series of novel ion-pair complexes based on TCNQ: syntheses, crystal structures and properties. CrystEngComm 2008. [DOI: 10.1039/b808390h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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71
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Syntheses, crystal structures, and magnetic properties of two novel Ni(mnt)2-based molecular magnetic materials containing substituted triphenylphosphinium. Inorganica Chim Acta 2008. [DOI: 10.1016/j.ica.2007.07.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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72
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Synthesis and characterization of half-sandwich Ir and Ru complexes containing Mnt ligand (Mnt=maleonitriledithiolate). INORG CHEM COMMUN 2007. [DOI: 10.1016/j.inoche.2007.07.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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73
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Tian Z, Ren X, Li Y, Song Y, Meng Q. A New Quasi-1D Spin System with Spin Transition Exhibiting Novel CN···π Interactions. Inorg Chem 2007; 46:8102-4. [PMID: 17824694 DOI: 10.1021/ic700758c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new molecular tecton with a flexible conformation, 1-methyl-ethyldeneaminopyridinium, was synthesized, and its corresponding compound with [Ni(mnt)(2)](-) exhibits novel CN...pi interactions and spin transition.
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Affiliation(s)
- Zhengfang Tian
- Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China
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74
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Ni C, Zhou J, Tian Z, Ni Z, Li Y, Meng Q. A spin gap transition around 230K observed in a new Ni(mnt)2-based molecular solid containing 1-(4′-nitrobenzyl)isoquinolinium. INORG CHEM COMMUN 2007. [DOI: 10.1016/j.inoche.2007.03.028] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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75
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Chen Y, Liu G, Wang P, Xu H, Ren X, Song Y, Sui Y. Mixed-valence molecular magnets based on building block: Structures, magnetic properties and DFT analyses. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.09.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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76
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Ren X, Nishihara S, Noro S, Akutagawa T, Nakamura T. 2D H-bonding molecular magnets based on [Ni(mnt)2]− monoanion: Syntheses, crystal structures and magnetic properties. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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77
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Ni C, Liu X, Yang L, Yu L. 3D network structure and magnetic behaviour of a new Ni(III) maleonitriledithiolate complex with C–H • • • π and π • • • π interactions using 4-dimethylaminopyridinium cation. J COORD CHEM 2007. [DOI: 10.1080/00958970601026988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Chunlin Ni
- a Department of Applied Chemistry , College of Science, South China Agricultural University , Guangzhou, 510642 P.R. China
- b Laboratory of Inorganic Functional Materials , South China Agricultural University , Guangzhou, 510642 P.R. China
| | - Xiaoping Liu
- a Department of Applied Chemistry , College of Science, South China Agricultural University , Guangzhou, 510642 P.R. China
| | - Lemin Yang
- a Department of Applied Chemistry , College of Science, South China Agricultural University , Guangzhou, 510642 P.R. China
| | - Linliang Yu
- a Department of Applied Chemistry , College of Science, South China Agricultural University , Guangzhou, 510642 P.R. China
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78
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Mochida T, Koinuma T, Akasaka T, Sato M, Nishio Y, Kajita K, Mori H. Hexagonal Supramolecular Architectures from Ferrocenium Cations Incorporating [Ni(mnt)2]− Columns: Structures and Properties of [Alkylferrocene][Ni(mnt)2]− Charge-Transfer Complexes (mnt=maleonitriledithiolate). Chemistry 2007; 13:1872-81. [PMID: 17136783 DOI: 10.1002/chem.200601275] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The crystal architecture, magnetic properties, and thermodynamic properties of [n-butylferrocene][Ni(mnt)2] (1), [tert-butylferrocene][Ni(mnt)2] (2), [1,1'-diethylferrocene][Ni(mnt)2] (3), and [1,1'-diisopropylferrocene][Ni(mnt)2] (4) were investigated (mnt=maleonitriledithiolate). These complexes exhibit a unique supramolecular structure in which the ferrocenium cations constitute honeycomb-like assembled structures surrounding columns of the anions. For 1, the cations form a dimer through a very short intermolecular ferrocene-ferrocene distance of 3.28 A, which mediates an antiferromagnetic interaction with a singlet-triplet energy gap of 5 K. First-order phase transitions occur in 1-3 at 364, 361, and 350 K, respectively, accompanied by thermal hysteresis.
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Affiliation(s)
- Tomoyuki Mochida
- Department of Chemistry, Faculty of Science, Toho University, Miyama, Funabashi, Chiba 274-8510, Japan.
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79
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Jeannin O, Clérac R, Fourmigué M. Order−Disorder Transition Coupled with Magnetic Bistability in the Ferricinium Salt of a Radical Nickel Dithiolene Complex. J Am Chem Soc 2006; 128:14649-56. [PMID: 17090051 DOI: 10.1021/ja064842v] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ferricinium salt of the anionic, S = (1)/(2), dithiolene complex [Ni(tfadt)(2)](-) (where tfadt is the asymmetrically substituted 2-(trifluoromethyl)acrylonitrile-1,2-dithiolate) crystallizes at room temperature (rt) into uniform chains of dithiolene complexes, separated by ferricinium cations. Both ionic entities are characterized by disorder affecting one CF(3) and one Cp moiety. Above 250 K, this compound displays a Curie-type behavior. At lower temperatures, two first-order transitions around 249 and 137 K are revealed by susceptibility measurements and the observation of hysteresis effects. Crystal structure determinations performed at 230 and 120 K show that the high-temperature transition is associated with an ordering of the CF(3) and Cp groups together with a dimerization of the anionic stacks that thus induces a drop of the susceptibility. The second, low-temperature transition leads to a tetramerization of these nickel dithiolene stacks now in a complete diamagnetic state while the remaining susceptibility originates from the sole ferricinium contribution. The first order character of the 249 K transition with its associated bistable behavior is likely correlated with the structural order-disorder transition, an original behavior in this class of materials where bistability is most often associated with a strengthening of interstack intermolecular interactions (hydrogen bonding, pi-pi interactions ...).
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Affiliation(s)
- Olivier Jeannin
- Laboratoire CIMMA, UMR 6200 CNRS-Université d'Angers, UFR Sciences, 2 Bd Lavoisier, 49045 Angers, France
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80
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Ren XM, Nishihara S, Akutagawa T, Noro S, Nakamura T, Fujita W, Awaga K, Ni ZP, Xie JL, Meng QJ, Kremer RK. Quasi-one-dimensional molecular magnets based on derivatives of (fluorobenzyl)pyridinium with the [M(mnt)2] monoanion (M = Ni, Pd or Pt; mnt2- = maleonitriledithiolate): syntheses, crystal structures and magnetic properties. Dalton Trans 2006:1988-94. [PMID: 16609769 DOI: 10.1039/b514278d] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The syntheses, structural characterizations and magnetic behaviors of three new complexes, 1-(3',4',5'-trifluorobenzyl)pyridinium [M(mnt)2]- [M = Ni (1), Pd (2) or Pt (3)], are reported. These complexes are isomorphous and their prominent structural character is that the [M(mnt)2]- anions form columnar stacks, in which the dimerization was observed. Complexes 2 and 3 are diamagnetic, while 1 possesses an energy gap of 2474 K. For crystal 4, 1-(4'-fluorobenzyl)pyridinium [Ni(mnt)2] (its structure and magnetic susceptibility were briefly reported earlier), the magnetic behavior can be divided into two regimes, namely, weakly ferromagnetic coupling above 93 K and strongly antiferromagnetic coupling below 93 K. A transition occurs at 93 K which switches the magnetic exchange nature from ferromagnetic to antiferromagnetic. A sharp thermal abnormality with lambda-shape, associated with the transition, appears from its heat capacity measurement to indicate that the transition is first order. The temperature dependences of the superlattice diffractions revealed the existence of the pretransitional phenomena up to at least 140 K. The unusual magnetic behavior of 4, such as the origin of the ferromagnetic interaction in the high temperature phase and what causes the spin transition, are discussed further.
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Affiliation(s)
- X M Ren
- Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan.
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81
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Ren XM, Nishihara S, Akutagawa T, Noro S, Nakamura T. Design of a Magnetic Bistability Molecular System Constructed by H-Bonding and π···π-Stacking Interactions. Inorg Chem 2006; 45:2229-34. [PMID: 16499388 DOI: 10.1021/ic051563k] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Crystal structures and magnetic properties were determined for two novel polymorphs of the complex [H2DABCO][Ni(mnt)2] [(H2DABCO)2+ = diprotonated 1,4-diazabicyclo[2.2.2]octane; mnt2- = maleonitriledithiolate]. For each polymorph, anions form a layered structure in which two kinds of dimers were observed. The adjacent anionic sheets are held together by cations via H-bonding interactions between protons of cations and CN groups of anions. Two polymorphs possess spin bistability; namely, upon cooling, a magnetic transition happens at around 120 K with about 1 K hysteresis on heating for the alpha phase and at 112 K with about 10 K hysteresis for the beta phase. Above the transition, the magnetic behaviors of two polymorphs can be approximately interpreted by a singlet-triplet model of an antiferromagnetically coupled S = 1/2 dimer, which is supported by the crystal structures and spin dimer analyses based on extended Hückel molecular orbital calculations.
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Affiliation(s)
- X M Ren
- Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan.
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82
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Ren X, Nishihara S, Akutagawa T, Noro S, Nakamura T, Fujita W, Awaga K. Novel spin transition observed in two quasi-one-dimensional spin system based on [M(mnt)2]− monoanion compounds (M = Ni or Pt; mnt2−= maleonitriledithiolate). Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2005.11.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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83
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Belo D, Figueira MJ, Nunes JPM, Santos IC, Pereira LC, Gama V, Almeida M, Rovira C. Magnetic properties of RBzPy[Ni(α-tpdt)2] (R = H, Br, F): effects of cis–trans disorder. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b603443h] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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