Near-infrared luminescence and solvent modulation of the magnetic relaxation behavior of dinuclear lanthanide complexess
| Autor: | Shao-Xia Huang, Hong-Ling Gao, Jian-Zhong Cui, Yao-Yao Nie, Zhen Liu, Xiao-Ya Chu, Wen-Min Wang, Hong-Man Chen |
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| Rok vydání: | 2018 |
| Předmět: |
Arrhenius equation
Lanthanide 010405 organic chemistry Chemistry Relaxation (NMR) 010402 general chemistry 01 natural sciences 0104 chemical sciences Inorganic Chemistry Solvent symbols.namesake Magnetization Crystallography Modulation Materials Chemistry symbols Magnetic relaxation Physical and Theoretical Chemistry Quantum tunnelling |
| Zdroj: | Polyhedron. 151:537-544 |
| ISSN: | 0277-5387 |
| DOI: | 10.1016/j.poly.2018.05.011 |
| Popis: | Seven new dinuclear centrosymmetric complexes, [Ln2(dbm)2L2(DMF)2]·2DMF (Ln = Nd (1), Eu (2), Tb (3), Dy (4), Er (5), Yb (6)) and [Dy2(dbm)2L2(CH3OH)2]·2CH3OH (7) (Hdbm = 1,3-diphenyl-1,3-propanedione, H2L = 2-[(2-(amino)benzhydrazide)-methyl]-8-hydroxylquinoline, DMF = dimethyl-formamide) have been synthesized and structurally characterized. Dynamic magnetic studies reveal the slow magnetic relaxation of complexes 4 and 7 are influenced by a fast quantum tunneling relaxation of the magnetization (QTM). However, the different magnetic relaxation behaviors were observed apparently in the two Dy2 complexes under a 3000 Oe dc field and modulated by the subtle change of solvents from DMF to CH3OH. For complex 7, the temperature dependence curves of in-phase (χ′) and out-of-phase (χ″) show better frequency-dependent signals, suggesting a slow relaxation of magnetization, typical of SMM behavior. Fitting the dynamic magnetic data of complex 7 to the Arrhenius law gives the energy barrier Ueff/kB = 44.06 K with the pre-exponential factor τ0 = 2.17 × 10−7 s under a 3000 Oe dc field. |
| Databáze: | OpenAIRE |
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