title: Modulating spin dynamics of cyclic LnIII-radical complexes (LnIII = Tb, Dy) by using phenyltrifluoroacetylacetonate coligand.
abstract: Three novel ring-like compounds formulated as [Ln(Phtfac)(3)(NITpPy)](2) (Ln(III) = Gd 1, Tb 2, Dy 3; HPhtfac = 4,4,4-trifluoro-1-phenylbutane-1,3-dione; NITpPy = 2-(4-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide) were synthesized and structurally and magnetically characterized. Three compounds possess cyclic dimer structure in which each pyridine substituted radical links two different metal ions through the oxygen of nitroxide group and the pyridine nitrogen. DC magnetic studies show the Ln(III) ion interacts ferromagnetically with the directly bonding nitronyl nitroxide. Both Tb(III) and Dy(III) clusters show frequency-dependent ac magnetic susceptibilities, indicating single-molecule magnet behavior. It is demonstrated that the β-diketonate coligand may play an important role in determining the magnetic relaxation for the lanthanide-radical system.
authors.affiliation: Department of Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, Nankai University, Tianjin, China.
authors.forename: Xue-Lan
authors.initials: XL
authors.lastname: Mei
authors.forename: Rui-Na
authors.initials: RN
authors.lastname: Liu
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Pei-Pei
authors.initials: PP
authors.lastname: Yang
authors.forename: Li-Cun
authors.initials: LC
authors.lastname: Li
authors.forename: Dai-Zheng
authors.initials: DZ
authors.lastname: Liao