title: Ligand Field Affected Single-Molecule Magnet Behavior of Lanthanide(III) Dinuclear Complexes with an 8-Hydroxyquinoline Schiff Base Derivative as Bridging Ligand.
abstract: New dinuclear lanthanide(III) complexes based on an 8-hydroxyquinoline Schiff base derivative and β-diketonate ligands, [Ln2(hfac)4(L)2] (Ln(III) = Gd (1), Tb (2), Dy (3), Ho (4), Er (5)), [Ln2(tfac)4(L)2] (Ln(III) = Gd (6), Tb (7), Dy (8), Ho (9)), and [Dy(bfac)4(L)2·C7H16] (10) (L = 2-[[(4-fluorophenyl)imino] methyl]-8-hydroxyquinoline, hfac = hexafluoroacetylacetonate, tfac = trifluoroacetylacetonate, and bfac = benzoyltrifluoroacetone), have been synthesized. The single-crystal X-ray diffraction data show that complexes 1-10 are phenoxo-O-bridged dinuclear complexes; each eight-coordinated center Ln(III) ion is in a slightly distorted dodecahedral geometry with two bidentate β-diketonate coligands and two μ2-O bridging 8-hydroxyquinoline Schiff base derivative ligands. The magnetic study reveals that 1 and 6 display cryogenic magnetic refrigeration properties, whereas complexes 3, 8, and 10 show different SMM behaviors with energy barriers of 6.77 K for 3, 19.83 K for 8, and 25.65 K for 10. Meanwhile, slow magnetic relaxation was observed in 7, while no out-of-phase alternating-current signals were found for 2. The different dynamic magnetic behaviors of two Tb2 complexes and the three Dy2 complexes mainly derive from the tiny crystal structure changes around the Ln(III) ions. It is also proved that the β-diketonate coligands can play an important role in modulating magnetic dynamics of the lanthanide 8-hydroxyquinoline Schiff base derivative system.
authors.affiliation: Department of Chemistry, Tianjin University , Tianjin 300072, People's Republic of China.
authors.forename: Wen-Min
authors.initials: WM
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Tianjin University , Tianjin 300072, People's Republic of China.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Tianjin University , Tianjin 300072, People's Republic of China.
authors.forename: Shi-Yu
authors.initials: SY
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Tianjin University , Tianjin 300072, People's Republic of China.
authors.forename: Hai-Yun
authors.initials: HY
authors.lastname: Shen
authors.affiliation: Department of Chemistry, Tianjin University , Tianjin 300072, People's Republic of China.
authors.forename: Hong-Ling
authors.initials: HL
authors.lastname: Gao
authors.affiliation: Department of Chemistry, Tianjin University , Tianjin 300072, People's Republic of China.
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Cui
authors.affiliation: College of Chemistry, Key Laboratory of Advanced Energy Material Chemistry, MOE, TKL of Metal and Molecule Based Material Chemistry, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao