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Two POM-based copper coordination polymers constituted by Keggin-type polyoxometalates (POMs), [Cu2 (SiW12O40)2 (Fbtx)3 (H2O)4]n (1) and {[Cu2 (SiW12O40) (Fbtx)2 (H2O)2.75]·4.5H2O}n (2) (Fbtx = 2,3,5,6-tetrafluoro-1,4-bis (1,2,4-triazole-1-ylmethyl)benenze) have been hydrothermally synthesized by the same precursor at different pH values and structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, element analyses and IR. Both of them have two-dimensional coordination layers constructed by bidentate SiW12O404− anions and bridging Fbtx ligands, in which complex 1 exhibits a 2D + 2D → 2D interpenetrated network with sql topology, while complex 2 features a binodal 3,5-connected network bearing new topology with a Schlafli symbol of {44;66}{62;10}. Additionally, the thermal stability, fluorescent properties and photocatalytic properties of complexes 1 and 2 have also been investigated. The results indicate that complexes 1 and 2 can serve as recyclable heterogeneous photocatalysts and show good catalytic activity for the degradation of Rhodamine B under UV irradiation.

A heterogeneous bifunctional hybrid catalyst originated from copper tetrasulfophthalocyanine (CuPcTs) and hydrotalcite for Baeyer–Villiger (B-V) oxidation has been prepared and characterized. XRD, FTIR, DR UV-Vis and SEM characterization indicate that CuPcTs molecule has been successfully intercalated into the layer of ZnAl hydrotalcite. And the synthesized hybrid exhibited excellent catalytic activity in the B-V oxidation for various ketones under mild conditions. Its bifunctional role in the reaction through O2/benzaldehyde has been discussed and verified by controlled experiments. The study indicates that the designed catalyst not only catalyzes the oxidation of benzaldehyde to perbenzoic acid, but also accelerates the transformation of ketone to lactone or ester.

5A zeolites were facilely synthesized from attapulgite clay and sodium aluminate precursors. The optimum synthesis condition for 4A zeolite (Na-form) were H2O/attapulgite ratio of 40:1 volume/mass, NaOH/attapulgite mass ratio of 2.35:1, the crystallization time was 4 h at 80–85 °C. The 4A zeolite was converted to related 5A zeolite (Ca-form) through ionic exchanges using calcium chloride solution with the Si/Al mole ratio of 1.3. SEM images demonstrated that as-synthesized 5A zeolites are ordered cubic crystals, average crystals length dimension is 1–2 μm. And the zeolites product had a specific surface area of 482 m2 g−1 and total pore volume of 0.274 cm3 g−1. The static adsorption experiments showed that the equilibrium adsorption capacities of n-decane and n-pentadecane on produced 5A zeolite were 0.253 and 0.510 g g−1, respectively. And the adsorption equilibrium time of n-decane and n-pentadecane on 5A zeolite were 45 and 60 min, respectively. The experimental adsorption data of n-decane and n-pentadecane on three zeolites could be properly fitted by the Langmuir–Freundlich isotherm model.

Chitosan, the only alkaline polysaccharide in the nature; phenylalanine, one of the essential amino acids, have a spacious application foreground in food industry. In this work, phenylalanine modified carboxymethyl chitosan (Ph-CMC) was synthesized; Ft-IR, 1H NMR and elemental analysis were used to characterize the structure of Ph-CMC. The effect of material mole ratio on substitution degree was determined, the substitution degree increased with the increase of material mole ratio between CMC and phenylalanine. The antimicrobial activity and preservative ability of Ph-CMC were investigated, as well. The results showed that Ph-CMC has strong antimicrobial activity and could efficiently lengthen the shelf-time of strawberries.

Three new coordination polymers, [Mn(BDC-F4)(DMF)2(H2O)2] n (1), [Ni(BDC-F4)(DMF)(EtOH)] n (2), and [Cd(BDC-F4)(DMF)(EtOH)] n (3), have been synthesized by assembling transition metal salts with the rigid ligand tetrafluoroterephthalic acid (H2BDC-F4) in mixed EtOH/DMF solvent at pH ca. 2. For complex 1, the octahedral coordination geometry of the MnII center is provided by two oxygen atoms from two dianionic BDC-F4 ligands, two DMF ligands and two aqua ligands, giving a 1-D linear chain array. For complex 2, the NiII center is coordinated by two dianionic BDC-F4 ligands, two EtOH ligands and two DMF ligands, resulting in a 1-D chain structure. For complex 3, the CdII center is coordinated by four dianionic BDC-F4 ligands, one EtOH ligand and one DMF ligand, generating a 2-D layered structure. The results suggest that both the metal and the solution pH play an important role in the formation of the complexes. The spectroscopic, thermal, and luminescence properties of the complexes have been investigated.

The low-level jet (LLJ) is closely related to severe rainfall events, air pollution, wind energy utilization, aviation safety, sandstorms, forest fire, and other weather and climate phenomena. Therefore, it has attracted considerable attention since its discovery. Scientists have carried out many studies on LLJs and made significant achievements during the past five or six decades. This article summarizes and assesses the current knowledge on this subject, and focuses in particular on three aspects: 1) LLJ classification, definition, distribution, and structure; 2) LLJ formation and evolutionary mechanisms; and 3) relationships between LLJ and rainfall, as well as other interdisciplinary fields. After comparing the status of LLJ research at home (China) and abroad, we then discuss the shortcomings of LLJ research in China. We suggest that this includes: coarse definitions of the LLJ, lack of observations and inadequate quality control, few thorough explorations of LLJ characteristics and formation mechanisms, and limited studies in interdisciplinary fields. The future prospects for several LLJ research avenues are also speculated.

The coordination chemistry of a rigid periodinated ligand, 2,3,5,6-tetraiodo-1,4-benzenedicarboxylic acid (H2BDC-I4), with a series of transition metal ions has been explored to afford five new coordination polymers {[M(BDC-I4)(MeOH)4](H2BDC-I4)(MeOH)2} n (M = ZnII for 1, CdII for 2, CoII for 3 and MnII for 4) and {[Mn(BDC-I4)(MeOH)4](DMF)} n (5). All these complexes have been characterized by elemental analysis, IR spectroscopy, thermogravimetric (TG) analysis, and X-ray crystallography. Single-crystal X-ray diffraction reveals that complexes 1–4 are isostructural and have a one-dimensional chain structure. Upon the addition of the solvent DMF, the infinite linear chain array in 4 is converted to a 1-D wave-like chain motif in 5 with a different space group ( $$ P\overline{1} $$ for 4 and P21/c for 5). The difference between structures 1–4 and 5 can be attributed to the coordination mode of carboxylate changing from trans to cis fashion. The ZnII and CdII complexes 1 and 2 display similar emissions in the solid state, which essentially are intraligand transitions.

Alumina-supported potassium (K/Al2O3) catalysts using pseudo-boehmite as the precursor were prepared by the impregnation/calcination method, characterised by XRD, SEM, ICP, N2 adsorption/desorption, CO2-TPD methods and TG analysis, and applied to the vapour-phase condensation of methyl propionate with trioxane to produce methyl methacrylate. The results showed the catalysts’ properties to be mainly affected by the calcined temperature (TC) and the crystal structure. The sample calcined at 1100°C exhibited the highest catalytic activity when mixed phases were formed and provided the appropriate specific surface area (SBET) and surface basic properties. The effects of TC, K-loading and reaction conditions on the catalytic performance were also investigated in a fixed-bed reactor. The yield of methyl methacrylate attained 29.2 % under the optimised conditions, and the deactivated catalyst could be completely regenerated by calcination.

Hollow CoFe2O4 spheres consisted of CoFe2O4 nanoparticles were synthesized by a facile solvothermal treatment of an ethylene glycol solution of FeCl3 · 6H2O, CoCl2 · 6H2O, and NaAc at 200 °C in the presence of polyethylene glycol and oleic acid. The products were characterized by powder X-ray diffraction, transmission electron microscopy, selected area electron diffraction, high-resolution transmission microscopy, scanning electron microscopy. The magnetic properties were evaluated using a vibrating sample magnetometer. The probable mechanism of the formation of Hollow CoFe2O4 spheres was discussed.