Self-assembled lanthanide-based helixes: synthetic control of the helical handedness by chirality of the ligand

The control of the self-assembly of lanthanide helical chain and their helical handedness have been investigated for the first time. Δ- and Λ-form lanthanide chain complexes were obtained by introducing thiazolidine ligands that were synthesised from L- and D-cysteine, respectively, and shared the same formula: [Ln₂(L)₃(H₂O)₅]_∞·3H₂O (Ln: Sm and Eu) (L: 2-(2-hydroxy-3,5-dinitrophenyl)thiazolidine-4-carboxylic acid). The crystallographic, circular dichroism, and luminescence properties of these novel lanthanide chain complexes were studied.

Homochiral Dysprosium Phosphonate Nanowires: Morphology Control and Magnetic Dynamics

Controllable synthesis of uniformly distributed nanowires of coordination polymers with inherent physical functions is highly desirable but challenging. In particular, the combination of chirality and magnetism into nanowires has potential applications in multifunctional materials and spintronic devices. Herein, we report four pairs of enantiopure coordination polymers with formulae S-, R-Dy(cyampH)₃  ⋅ CH₃ COOH ⋅ 2H₂ O (S-1, R-1), S-, R-Dy(cyampH)₃  ⋅ 3H₂ O (S-2, R-2), S-, R-Dy(cyampH)₂ (C₂ H₅ COO) ⋅ 3H₂ O (S-3, R-3) and S-, R-Dy(cyampH)₃  ⋅ 0.5C₂ H₅ COOH ⋅ 2H₂ O (S-4, R-4) [cyampH₂ =S-, R-(1-cyclohexylethyl)aminomethylphosphonic acids], which were obtained depending on the pH of the reaction mixtures and the specific carboxylic acid used as pH regulator. Interestingly, compounds 3 were obtained as superlong nanowires, showing 1D neutral chain structure which contains both phosphonate and propionate anion ligands. While compounds 1, 2 and 4 appeared as block-like crystals, superhelices and nanorods, respectively, and exhibited similar neutral chain structures containing only phosphonate ligand. Slow magnetization relaxation characteristic of single-molecule magnet (SMM) behavior was observed for compounds S-1 and S-3. Theoretical calculations were performed to rationalize the magneto-structural relationships.

Modulation of the properties of dinuclear lanthanide complexes through utilizing different β-diketonate co-ligands: near-infrared luminescence and magnetization dynamics

Four Dy₂ complexes based on the ligand H₂L display various slow magnetic relaxation behaviors through utilizing different β-diketonate co-ligands.

Structural investigation of one- and three-dimensional lanthanide(III) coordination polymers based on functionalized terpyridine carboxylate and aromatic dicarboxylate ligands

Three series of lanthanide coordination polymers, namely catena-poly[[lanthanide(III)-μ2-(benzene-1,2-dicarboxylato)-μ2-[2-(2,2′:6′,2′′-terpyridin-4′-yl)benzoato]] monohydrate], {[Ln(C8H4O4)(C22H14N3O2)]·H2O} n or {[Ln(1,2-bdc)(L)]·H2O} n , with lanthanide (Ln) = dysprosium (Dy, 1), holmium (Ho, 2) and erbium (Er, 3), poly[bis(μ2-benzene-1,3-dicarboxylato)bis[μ2-2-(2,2′:6′,2′′-terpyridin-4′-yl)benzoato]dilanthanide(III)], [Ln2(C8H4O4)2(C22H14N3O2)2] n or [Ln2(1,3-bdc)2(L)2] n , with Ln = gadolinium (Gd, 4), Ho (5) and Er (6), and poly[(μ2-benzene-1,4-dicarboxylato)[μ2-2-(2,2′:6′,2′′-terpyridin-4′-yl)benzoato]lanthanide(III)], [Ln(C8H4O4)(C22H14N3O2)] n or [Ln(1,4-bdc)(L)] n , with Ln = Dy (7), Ho (8), Er (9) and ytterbium (Yb, 10), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compounds 1–3 possess one-dimensional loop chains with Ln2(COO)2 units, which are extended into three-dimensional (3D) supramolecular structures by π–π interactions. Isostructural compounds 5 and 6 show 6-connected 3D networks, with pcu topology consisting of Ln2(COO)2 units. Compounds 7–10 display 8-connected 3D frameworks with the topological type rob, consisting of Ln2(COO)2 units. The influence of the coordination orientations of the aromatic dicarboxylate groups on the crystal structures is discussed.

Tetranuclear rare-earth complexes: energy barrier enhancement and two-step slow magnetic relaxation activated by ligand substitution

The influence of tuning the β-diketone on the modulation of the magnetic properties is demonstrated.

A belt-like one-dimensional Dy chain exhibiting slow magnetic relaxation behavior

A belt-like Dy chain compound was synthesized, which exhibited slow magnetic relaxation behavior and clear hysteresis loops below 0.6 K.

Modulating single-molecule magnet behavior towards multiple magnetic relaxation processes through structural variation in Dy4 clusters

Three Dy₄ clusters based on a flexible and attractive Schiff base ligand HL have been synthesized, and they showed different tetranuclear core arrangements. Magnetic studies reveal that clusters 1–3 display distinct slow relaxation of magnetization.

Two lanthanide metal–organic frameworks constructed from tris(4-carboxyphenyl)phosphane oxide with gas adsorption and magnetic properties

Based on the tripodal tris(4-carboxyphenyl)phosphane oxide ligand, two lanthanide metal–organic frameworks were obtained, with 1 showing highly selective gas adsorption of CO₂/CH₄ and 2 exhibiting direct and alternating current magnetic properties.

Modulating the magnetization dynamics of four phenoxo-O bridged Dy2 complexes based on a Schiff base derived from 8-hydroxyquinoline

The quantum tunneling process in Dy-SMMs is suppressed by the application of a dc field.

Fine-tuning the magnetocaloric effect and SMMs behaviors of coplanar RE4 complexes by β-diketonate coligands

By introducing different β-diketonate coligands, Gd₄ complexes show cryogenic magnetic refrigeration properties, whereas Dy₄ clusters exhibit different SMMs behaviors.

pH-Dependent Self-Assembly of Ladder-Like Lanthanide Chains with Copper(I) Halide Clusters

Through adjustment of the pH value of the reaction system, two series of 3 D lanthanide(III)-copper(I) coordination polymers, namely [Ln₂ (na)₇ Cu₆ Br₅ (H₂ O)₂ ] [Ln=La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8)] and [La₂ (na)₇ Cu₃ Br₂ (H₂ O)₂ ]⋅H₂ O (9) (na^- =nicotinate), are synthesized hydrothermally and characterized fully. It is worth nothing that these two series of heterometallic compounds are constructed from similar ladder-like Ln-organic chains, but different copper(I) halide clusters. The luminescence properties of the compounds with Nd (4), Eu (6), and Tb (8) are also investigated.

Field and dilution effects on the magnetic relaxation behaviours of a 1D dysprosium(iii)-carboxylate chain built from chiral ligands

A novel enantiomer-pure dysprosium chain shows various slow magnetic relaxation behaviours depending on the field and dilution effects.

A Dy2 single-molecule magnet with benzoate anions and phenol-O− bridging groups

A Dy₂ single-molecule magnet, namely [Dy₂(H₃L)₂(PhCOO)₄]·4H₂O (1), was obtained from the reaction of Dy(PhCOO)₃ with 1,5-bis(2-hydroxy-3-methoxybenzylidene)carbonohydrazide (H₄L).