Ligand substitution effect on single-molecule magnet behavior in dinuclear dysprosium complexes with radical functionalized phenol as bridging ligands.
Reaction of Dy(hfac)(3)·2H(2)O (hfac = hexafluoroacetyl acetonate) with 2-(2-hydroxyphenyl)nitronyl nitroxide (NITPhOH) and 2-(5-bromo-2-hydroxyphenyl)nitronyl nitroxide (NIT5BrPhOH) yielded [Dy(2)(hfac)(4)(NITPhO)(2)] 1 and [Dy(2)(hfac)(4)(NIT5BrPhO)(2)] 2, respectively. These compounds are phenoxo-O bridged binuclear complexes with the radical unit of a ligand coordinated to a single Dy. The Ln centers exhibit a heptacoordinated environment. Despite having very similar structures, these compounds exhibit distinct magnetic behaviors. Compound 1 shows slow relaxation of its magnetization indicating single-molecule magnet behavior, while no frequency-dependent out-of-phase signals were found for complex 2. This difference is likely to result from electronic effects induced by halogen substitution.
Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, Nankai University, Tianjin 300071, China.
Ruina
R
Liu
Congming
C
Zhang
Licun
L
Li
Daizheng
D
Liao
Jean-Pascal
JP
Sutter