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Using rational designed chalcone dicarboxylic acid ligand (H2L), a series of lanthanide metal–organic frameworks (Ln–MOFs) with the general formula Ln(HL)3 (Ln = La; Ce; Pr; Nd; Sm; Eu; Gd) have been obtained under the solvothermal reaction. The crystal structure analysis displays that all the Ln–MOFs are the isomorphic three-dimensional (3D) metal–organic frameworks with honeycomb cavities, in which the porosity is ∼20% that calculated via PLATON software. In addition, photocatalytic activities of Ln–MOFs for the degradation of several organic dyes have been explored, suggesting that Ln–MOFs can be used as efficient heterogeneous photocatalyst for the degradation of organic dyes.

A novel phenylthiourea modified Mn-Anderson polyoxometalate, [N(C4H9)4]3[MnMo6O18{(OCH2)3CNHCSNHPh}{(OCH2)3CNH2}] (1) has been synthesized and characterized by IR, NMR, UV–Vis spectroscopy, thermogravimetric, electrochemical and single-crystal X-ray diffraction analysis. Structural analysis reveals that compound 1 crystallizes in the orthorhombic crystal system, space group Pcab with a = 17.7477(9) A, b = 33.6245(16) A, c = 32.322(2) A, V = 19288.7(19) A3 and Z = 8. Noticeably, the asymmetric POM cluster with terminal modification could be connected through H-bonding interactions of C H⋯O to form an infinite supramolecular chain. Furthermore, the adjacent 1D chains are linked by H-bonding interactions of N H⋯O to generate a 2D supramolecular layer.

By taking advantage of the synthetic 8-hydroxyquinoline derivative, (E)-2-[2-(4-chlorophenyl)vinyl]-8-hydroxyquinoline (HL), three new metal–organic coordination compounds [Zn3L6] (1), [Cd3L6] (2) and [Cu2L4] (3) have been obtained by solvothermal or solution processing methods and structurally characterized. Single crystal X-ray diffraction analysis revealed that complexes 1 and 2 have similar ‘V’-type trinuclear structures. Different from complexes 1 and 2 (trinuclear structure), complex 3 displays dinuclear structure. The effects of central metals and reaction solvents on the structures of complexes 1–3 have been discussed. Furthermore, thermogravimetric analysis and solid state fluorescence of ligand HL, 1–3 were investigated.

Five ion-pair complexes, consisting of R-benzylidene-1-aminopyridinium derivatives and [Ni(mnt)2]2− (R = p-nitro (1), p-methyl (2), p-bromo (3), p-chloro (4) and m-nitro (5); mnt2− = maleonitriledithiolate), were synthesized and structurally characterized. As for 1, it is interesting to observe a large deviation from square-planar coordination geometry for the Ni atom, while no deviation is observed in the other four complexes. In the solid state, UV–Vis–NIR spectra of 2–5 show similar properties with intense absorption in the 200–750 nm and moderate near IR absorption in the 750–1000 nm region, whereas 1 exhibits an intense absorption from UV/Visible to near-IR region (200–1100 nm). This unique spectral feature of 1 is attributed to its distinctive structural differences from 2 to 5, namely the strong intermolecular packing interactions between anions and cations, as well as a significant deviation from the planarity of the anion. Based on DFT and TDDFT calculations, near-IR absorbance bands in 1–5 were assigned to combined transitions of d–d, MLCT and π–π∗ in the [Ni(mnt)2]2− anion as well as the ion-pair charge transfer (IPCT) from the anionic HOMO to the cationic LUMO. The IPCT band position in acetonitrile is independent of the substituent group feature in benzene ring of cations for 1–5, which could be interpreted that the substituent group in benzene ring only has a minor contribution to the cationic LUMO.

Two compounds of composition [FBzPy][Pt(mnt) 2 ] ( 1 ) and [FBzPy][Pt(mnt) 2 ] · 0.25-MeCN ( 2 ) ([FBzPy] + = 1-(4′-fluorobenzyl)pyridinium and mnt 2− = maleonitriledithiolate) were prepared and their crystal structures were determined. The solvent molecule, MeCN, incorporated into lattice leads the anionic stacking pattern to be distinct between 1 and 2 . The regular anionic stacking columns are connected by the anionic dimers to construct into 2D anionic networks in 1 , while the anionic fourfold subunit develop into anionic layers though lateral S⋯S interactions in 2 . As for two compounds, the magnetic susceptibilities in 2–350 K were measured, and the magnetic exchange schemes were built based on the analyses both crystal structures and extended Huckel molecular orbital calculations. The magnetic coupling model of an alternating AFM Heisenberg chain with an isolated AFM coupling dimer was dealt with 1 , while a spin dimer with s = 1/2 with 2 , and the magnetic coupling parameters were further gained via simulating the temperature dependent magnetic susceptibility data of two compounds.

Two new ion-pair complexes [1-(4′-fluorobenzyl)pyridinium][Ni(bdt)2] (1) and [1-(4′-bromobenzyl)pyridinium][Ni(bdt)2] (2), in which bdt2−=1,2-benzenedithiolate (‘S2’2−), have been prepared and characterized. X-ray structural analyses showed that 1 and 2 are isostructural, and the anions are centrosymmetric. The 2 non-equiv. anions form different uniform-spaced stacking pattern in 1 and 2. The magnetic measurements of 1 and 2 indicate ferromagnetic behavior in the antiferromagnetic exchange system, which may arise from spin canting. Cyclovoltammetry revealed two quasi-reversible one-electron steps for 1 and 2, which are attributed to Ni(IV/III) and Ni(III/II) redox couples.