Dinuclear Dysprosium Complexes Research Articles

Magnetic anisotropy and interaction between f-electronic systems in dinuclear inverted-sandwich-type lanthanide-phthalocyanine complexes

The first detection and characterization of magnetic interaction between two 4f electronic systems in the dinuclear "inverted-sandwich-type" phthalocyanine complex with terbium ions and that of dysprosium ions are presented. Temperature dependent magnetic measurements for the diterbium complex, (μ-phthalocyaninato)bis[di(2,2,6,6-tetramethylheptane-3,5-dionato)terbium], show that the value of magnetic susceptibility times temperature, χT, sharply decreases as temperature is lowered, indicating the presence of an antiferromagnetic-type interaction between the Tb 3+ ions in the dinuclear complex. Similar temperature dependence was observed for the corresponding dinuclear dysprosium complex. These results are completely opposite to those observed for Pc triple-decker dinuclear terbium or dysprosium complexes, which are known to function as single molecule magnets. The NMR signals for the protons on the Pc ligand of the diterbium complex show up-field paramagnetic shifts due to the partially-filled 4f shells of the metal ions. This again makes sharp contrast to the triple-deckers, for which large down-field paramagnetic shifts are observed. These intriguing results seen in the NMR and magnetic susceptibility measurements are explained assuming the ligand field potential of the inverted-sandwich complexes gives strong easy-plain-type magnetic anisotropy, where Jz value of the lowest sublevel has a small value, while sandwich-type Pc3Ln2 ( Ln = Tb or Dy ) complexes have a strong easy-axis-type magnetic anisotropy.

Hybrid Nanomaterials: Anchoring Magnetic Molecules on Naked Gold Nanocrystals

The pairing of molecular magnets and nanomaterials couples top-down and bottom-up approaches to nanotechnology; facilitating a unique methodology to the controlled study of interfacial magnetic properties. Attaching Single-Molecule Magnets (SMMs) to "naked" gold nanoparticles is a novel method of exploring various avenues of magnetic nanotechnology, such as drug delivery, information storage, catalysis, and assembly of magnetic-nanostructural motifs. Herein we report the successful capping of laser ablation synthesized "naked" gold nanoparticles with a dinuclear dysprosium complex, while introducing new information regarding the changes in molecular magnetic properties upon surface attachment. We anticipate that this methodology in producing these magneto-plasmonic nanostructures not only provides answers to fundamental questions but also has the potential to provide new avenues to applications including information storage, multimodal imaging, biomedicine, and optoelectronics.

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.

Tetrakis(μ-3,4-dimethoxyphenylacetato)bis[(3,4-dimethoxyphenylacetato)(1,10-phenanthroline)dysprosium(III)

The title centrosymmetric dinuclear dysprosium(III) complex, [Dy2(C10H11O4)6(C12H8N2)2] or [Dy(L)3phen]2, is comprised of six 3,4-dimethoxy­phenylacetate (L) anions, two 1,10-phenanthroline (phen) mol­ecules and two DyIII ions. The DyIII atom is nine-coordinated by seven O atoms from five L ligands and two N atoms from the phen mol­ecules. The L ligands are coordinated to the DyIII ion in three coordination modes: chelating, bridging and bridging-tridentate. C—H⋯O hydrogen bonding interactions consolidate the crystal packing.

The first polymeric thiogallate with lanthanide-containing counter cation, [Dy 2(en) 6(μ 2-OH) 2]Ga 4S 8

The title compound, [Dy 2(en) 6(μ 2-OH) 2]Ga 4S 8 (en = ethylenediamine), contains 1D infinite sinusoidal [ GaS 2 - ] n anions and hydroxy bridged dinuclear dysprosium complex cations. Two bridging hydroxy ions connect two inversion-related Dy 3+ ions to form a centrosymmetric dimer, in which a Dy 2O 2 rhomboidal core is formed. The title compound is the only example of the thiogallates with lanthanide-containing counter cation.