To develop new lanthanide single-molecule m a g n e t s ( S M M s ) , t w o n e w c o m p l e x e s o f [Dy 2 (MeOH) 2 (HL 1 ) 2 (NO 3 ) 2 ]•2MeOH (1) and [Dy 6(2) were obtained by reacting Dy(NO) 3 •6H 2 O with 3-amino-1,2-propanediol in the presence of 2-hydroxynaphthaldehyde for 1 and by reacting DyCl 3 •6H 2 O with 1,1-di-(hydroxymethyl)ethylamine in the presence of 2-hydroxynaphthaldehyde for 2, respectively, in which the Schiff base ligands of 3-(((2-hydroxynaphthaen-1-yl)methylene)amino)propane-1,2-diol (H 3 L 1 ) and 2-(β-naphthalideneamino)-2-(hydroxylmethyl)-1-propanol (H 3 L 2 ) were in situ formed. The two Dy(III) ions in 1 are linked by two O alkoxy atoms of two (HL 1 ) 2− ligands to build a dinuclear skeleton. Complex 2 presents a nearly planar hexanuclear skeleton constructed from four edge-shared triangular Dy 3 units with the two peripheral Dy 3 units consolidated by two μ 3 -O bridges and the two central Dy 3 units consolidated by one μ 3 -O bridge. Obviously, they exhibit a different topological arrangement resulting from the linkage of the Schiff base ligands. Both of them are typical SMMs under zero dc fields, with a U eff /k B value of 34 K for 1 and 40 K for 2, respectively. Multiple processes are involved in the relaxation processes of 1 and 2. The different SMM performances of the two titled complexes reveal a tuning effect of Schiff base ligands through tuning the coordination environments and topological arrangements of dysprosium(III) ions, which is supported by the theoretical calculations.

The generation of two types of complexes with different topological connections and completely different structural types merely via the substitution effect is extremely rare, especially for −CH 3 and −C 2 H 5 substituents with similar physical and chemical properties. Herein, we used 3-methoxysalicylaldehyde, 1,2-cyclohexanediamine, and Dy(NO 3 ) 3 •6H 2 O to react under solvothermal conditions (CH 3 OH:CH 3 CN = 1:1) at 80 °C to obtain the butterfly-shaped tetranuclear Dy III cluster [Dy 4 (L 1 ) 4 (μ 3 -O) 2 (NO 3 ) 2 ] (Dy 4 , H 2 L 1 = 6,6′-((1E,1′E)-(cyclohexane-1,3-diylbis(azanylylidene))bis(methanylylidene))bis(2-methoxyphenol)). The ligand H 2 L 1 was obtained by the Schiff base in situ reaction of 3-methoxysalicylaldehyde and 1,2-cyclohexanediamine. In the Dy 4 structure, (L 1 ) 2− has two different coordination modes: μ 2 -η 1 :η 2 :η 1 :η 1 and μ 4η 1 :η 2 :η 1 :η 1 :η 2 :η 1 . The four Dy III ions are in two coordination environments: N 2 O 6 (Dy1) and O 9 (Dy2). The magnetic testing of cluster Dy 4 without the addition of an external field revealed that it exhibited a clear frequency-dependent behavior. We changed 3-methoxysalicylaldehyde to 3ethoxysalicylaldehyde and obtained one case of a hydrogen-bonded helix framework, [DyL 2 (NO 3 ) 3 ] n •2CH 3 CN (Dy-HHFs, H 2 L 2 = 6,6′-((1E,1′E)-(cyclohexane-1,3-diylbis(azanylylidene))bis(methanylylidene))bis(2ethoxyphenol)), under the same reaction conditions. The ligand H 2 L 2 was formed by the Schiff base in situ reaction of 3ethoxysalicylaldehyde and 1,2-cyclohexanediamine. All Dy III ions in the Dy-HHFs structure are in the same coordination environment (O 9 ). The twisted S-shaped (L 2 ) 2− ligand is linked by a Dy(III) ion to form a spiral chain. The spiral chain is one of the independent units that is interconnected to form Dy-HHFs through three strong hydrogen-bonding interactions. Magnetic studies show that Dy-HHFs exhibits single-ion-magnet behavior (U eff = 68.59 K and τ 0 = 1.10 × 10 −7 s, 0 Oe DC field; U eff = 131.5 K and τ 0 = 1.22 × 10 −7 s, 800 Oe DC field). Ab initio calculations were performed to interpret the dynamic magnetic performance of Dy-HHFs, and a satisfactory consistency between theory and experiment exists.

A carboxy-functionalized covalent organic framework COOH@COF for efficient removal of Pb2+ and Hg2+ ions from water has been prepared. Fourier transform infrared spectroscopy, solid-state 13C NMR spectra, and elemental analysis indicate that the carboxy function has been grafted to COF materials via the click reaction. Its crystallinity remains unchanged after post-synthetic modification, as confirmed by the powder X-ray diffraction. Scanning electron microscopy images reveal that the COOH@COF possesses the thorn ball structure assembled by numerous nanowires with a diameter of 90 nm. This COOH@COF features excellent adsorption capacities for Pb2+ (123.8) and Hg2+ (99.1 mg/g) in water. The adsorption isotherms follow the Langmuir model, and their kinetics adsorption fits the pseudo-second-order model. Particularly, the COOH@COF can be recycled 20 times without loss of the adsorption capacity in water, showing its latent potential for practical application in the future.

Chiral lanthanide clusters provide a platform for molecular-based materials with coordination between chirality and magnetism, and exhibited great application prospects in the fields of three-dimensional displays, magneto-optical memories, and spintronic...

Two new [Dy4]-based coordination clusters [Dy4(L1)2(L2)4(NO3)2(EtOH)4]·2MeOH (1) (H3L1 = 2-(β-naphthalideneamino)-2-(hydroxylmethyl)-1-propanol, HL2 = 2-hydroxy-1-naphthaldehyde) and [Dy4(µ4-O)(HL3)4(H2L3)2]·3H2O·EtOH·CH3CN (2) (H3L3 = 3-(((2-hydroxynaphthaen-1-yl)methylene)amino)-propane-1,2-diol) with planar and butterfly-like skeleton, respectively, were synthesized and characterized. It...