Slow Relaxation Processes and Single-Ion Magnetic Behaviors in Dysprosium-Containing Complexes

Abstract

A series of one-dimensional complexes [Ln(L(1))(3)(HOCH(2)CH(2)OH)](n) (L(1) = 2-furoate anion; Ln = Nd (1), Sm (2), Gd (3), Tb (4), Dy (5), Er (6)) have been synthesized. The complexes were crystallized in the monoclinic space group P2(1)/c and show a chain-like structure determined by single-crystal X-ray diffraction. Magnetic properties indicate that carboxyl group of 2-furoate mediates different magnetic couplings in light and heavy rare earth complexes, namely, antiferromagnetic interaction between light rare earth ions and ferromagnetic interaction between heavy ones. Noticeably, complex 5 displays a strong frequency dependence of alternating current (AC) magnetic properties. Further magnetic studies show a distribution of a single relaxation process in 5. While 1,10-phenanthroline and phthalate anion (L(2)) were employed, [Dy(2)(L(2))(6)(H(2)O)](n) (7) was isolated by hydrothermal reactions and characterized magnetically. Research results also show the frequency dependence of AC magnetic susceptibilities, although the phthalate anions mediate antiferromagnetic coupling between Dy(III) ions. Further magnetic investigation of a neutral mononuclear complex with the formula [Dy(TTA)(3)(L(3))] (8) (TTA = 2-thenoyltrifluoroacetonate; L(3) = 4,5-pinene bipyridine) suggests that the single-ion magnetic behavior originates the slow relaxation of Dy(III)-containing complexes.

Slow Magnetic Relaxation in Chiral Helicene-Based Coordination Complex of Dysprosium

“…The Dy III ion, with its 6 H 15/2 ground state, easily leads to Ising type of magnetic anisotropy in coordination spheres like N 2 O 6 and this is achieved with the common bidentate 2,2 -bipyridine (bpy) ligand and three hfac − ligands [13,[28][29][30]. On the other hand, a 2,2 -bipyridine (bpy) ligand has been functionalized with a [6]-helicene to enhance the luminescence.…”

Field‐Induced Slow Magnetic Relaxation in a Mononuclear Manganese(III)–Porphyrin Complex

“…[2] In contrast, SIMs depend on the magnetic properties of as ingle paramagnetic ion generally in ah igh spin state. Since the discovery of bis(phthalocyanine)-lanthanide(III) complexes, further examples of SIMs that contain otherl anthanides [3][4][5][6][7][8][9][10][11][12][13][14][15][16] and actinides have been reported, [17][18][19][20][21] followed by first-and third-row transition-metal ions, [22] such as Fe II , [23][24][25][26][27][28][29] Co II , [30][31][32][33][34] Mn III , [35][36][37][38][39] Ni I , [40] and Re IV . [41] A variety of ligands, which serve to controlt he molecular symmetry of the metal-coordinatione nvironmenta nd thus the zero-field splitting (zfs) of the final complex, were used in the design andp reparation of theseSIMs.…”

A Non‐sandwiched Macrocyclic Monolanthanide Single‐Molecule Magnet: The Key Role of Axiality

“…This finding is general for lanthanide complexes. For instance, recently a series of Dy III -based compounds [25] have shown similar behavior of AC susceptibility, that is, no maxima of c" unless a DC field was applied. On this basis, future strategies for the synthesis of efficient lanthanide-based SMMs (initially to get blocking of the magnetization, a maximum in c", without applying a DC field, then optimizing the barrier) should be directed towards the use of highly axial single-lanthanide building www.chemeurj.org blocks.…”