One-pot mechanochemical synthesis was demonstrated to be an efficient strategy to synthesize host–guest POM⊂rho-ZIF complexes (POM = polyoxometalate; rho-ZIF = zeolitic imidazolate framework with rho topology) with high crystallinity. In this work, the metastable rho-ZIF with large interior cavities and windows was used as host matrix for encapsulating and immobilizing bulky guest molecules with high loading efficiency and chemical stability. As novel catalysts, POM⊂rho-ZIF complexes were found effective for the selective oxidation of a series of sulfides to sulfoxides. Moreover, the heterogeneity of these composite catalysts was confirmed by leaching tests, and they can be recycled at least four times without significant loss of activity.

A new potassium lutetium borate, K3LuB6O12, was synthesized by a flux method and the crystal structure was determined by the single crystal X-ray diffraction. It crystallizes in non-centrosymmetric space group R32 and features a three-dimensional framework that is composed of B5O10, KO6, KO8, LuO6 and (K|Lu)O6 groups. Band structure calculations by the density functional theory method indicate that K3LuB6O12 has direct bond gap of about 2.84 eV. The optical absorption can be mainly ascribed to the charge transitions from the O-2p states to the Lu-6s and Lu-5d states. Moreover, Eu-doped phosphor K3Lu0.95Eu0.05B6O12 was synthesized by a solid-state reaction and its photoluminescence properties were studied. Under near-UV excitation (393 nm), K3Lu0.95Eu0.05B6O12 exhibits an intense red emission centered at around 611 nm with the CIE coordinate of (0.641, 0.357), which can be assigned to the electric dipole 5D0 → 7F2 transition of Eu3+ ions. We think that K3Lu0.95Eu0.05B6O12 may be used as a good red phosphor pumped by near UV light LED chips.

Through postsynthetic modification of ligand struts, controllable conversion of a Zr MOF between rigidity and flexibility is realized. The rationally prepared flexible MOF exhibits interesting dynamic behaviours, such as reversible structural deformation, vapour sorption hysteresis and unexpected adsorption of bulky guest molecules.

•We study the detailed crystal structure of yavapaiite-type orthophosphate BaTi(PO4)2.•The structure solution is complicated by non-merohedral twinning.•The electronic properties of the compound were studied by DFT method.•The photoluminescence properties of the compound are described.A ternary orthophosphate BaTi(PO4)2 has been prepared using a high temperature molten salt method and structurally determined by single crystal X-Ray diffraction analysis. It crystallizes in yavapaiite-type structure with monoclinic space group C2/m. The structure was refined by a non-merohedral twinning model with the twin law (−0.435 1.4350 −0.564 −0.435 0 0.097 −0.099 1). Band structure calculation using the density functional theory (DFT) method indicates that BaTi(PO4)2 has a direct bond gap of about 3.00 eV, which is well fitted with the experimental value of 2.95 eV. The photoluminescence excitation and emission spectra, decay curve, and the color coordinates for BaTi(PO4)2 were investigated. It can be efficiently excited by UV light (270 nm) and presents blue–green emission (centered at 506 nm), which may be attributed to the lattice defect emission.For the first time, the detailed crystal structure of BaTi(PO4)2 was studied by a non-merohedral twinning model. Theoretical studies show that it has direct optical transitions which can be assigned to the charge transfer from O-2p to Ti-3d states. The photoluminescence emission ranging from 400 nm to 700 nm is originated from the self-trapped exaction recombination.

•A new red phosphor K3EuB6O12 was prepared.•The crystal structure of K3EuB6O12 was determined for the first time.•The photoluminescence properties of K3EuB6O12 are studied.•K3EuB6O12 show intense self-activated red emission under near-UV light excitation.A new potassium europium borate K3EuB6O12 has been prepared using a high temperature molten salt method and structurally characterized by single crystal X-ray diffraction (SC-XRD) analyses. Its structure features a three-dimensional (3D) framework composed of isolated [B5O10]5− anions that are bridged by K+ and Eu3+ ions. In this structure, one crystallographic distinct atom site is mixed occupied by K/Eu at a molar ratio of 1:1. The self-activated photoluminescence (PL) of K3EuB6O12 was studied. The excitation spectrum covers a wide range from 322 to 466 nm, which suggests that the K3EuB6O12 phosphors can be effectively excited by a near-UV light source. The emission spectrum consists of groups of lines in the red spectral region due to the 5D0→7Fj (j = 1, 2, 3, 4) electronic transitions of Eu3+ ions, with the most intense line at 611 nm. We may expect that K3EuB6O12 has the potential to be a red phosphor pumped by near-UV LED chips.

By employment of sulfonate-decorated metal–organic cuboctahedra (MOCs) as tectons, we report an interesting example of molecular tectonics strategy for the rational construction of three-dimensional (3D) porous network 1 through complementary and metrically matched N–H+···–O–S hydrogen bonds between guanidinium and sulfonate (GS) moieties. Built from the MOCs as 24-connected nodes and the GS H-bonding motifs as 3-connected nodes, 1 was expected to have a (3,24)-connected network topology, which has been verified by the single crystal X-ray analysis. In addition, the porous H-bonding network 1 displays good stability under ambient conditions and modest absorption of cationic dye molecules.

Through postsynthetic modification of ligand struts, controllable conversion of a Zr MOF between rigidity and flexibility is realized. The rationally prepared flexible MOF exhibits interesting dynamic behaviours, such as reversible structural deformation, vapour sorption hysteresis and unexpected adsorption of bulky guest molecules.