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Pyridyl‐pyrrole ligands usually mimic the polypyridine ligand, and their metal complexes are interesting due to their rich coordination chemistry and their use in molecular devices, biological therapeutics, and catalytic transformations. Cs‐symmetric HL3 ligand Br‐substituted on one of the pyridyl rings was designed and synthesized by Paal–Knorr pyrrole condensation. Ligand HL4 was synthesized by Suzuki‐coupling reaction between HL3 and 2‐thiopheneboronic acid in the presence of K2CO3 and Pd(PPh3)4 in degassed THF/H2O solution. Zinc complexes 1–5 with HL1 to HL5 were prepared by treatment of the corresponding pyridyl‐pyrrole ligands with diethylzinc in toluene at 0 °C in high yield. Ligand HL3 and all zinc complexes are characterized by X‐ray diffraction analysis. The structure of free HL3 is planar. The geometries at Zn in 1, 2, and 5 are compressed octahedra, while in 3 and 4 they are perhaps best described as being between cis‐divacant octahedral and distorted tetrahedral. In these zinc complexes, shorter Zn–Npyrrole [1.878(5)‐1.950(4) Å] and longer Zn–Npyridine [2.108(5)‐2.509(3) Å], Zn‐Npendant pyridine [2.802(2)‐3.039(3) Å] bond lengths are observed. Complexes 2 and 3 were used as catalysts to promote the coupling reaction of CO2 and various epoxides under solvent‐free conditions, and the catalytic mechanism was investigated by 1H NMR spectroscopy. Zinc complexes with tridentate pyridyl‐pyrrole ligands were synthesized and fully characterized by NMR, IR, and UV/Vis spectroscopy and X‐ray diffraction. These zinc complexes were used as efficient catalyst for the coupling reaction of epoxides and CO2 to form cyclic carbonates with low catalyst loading at ambient temperature and normal pressure under solvent‐free conditions. [ABSTRACT FROM AUTHOR]

Novel composite photocatalysts consisting of CdS and graphitic carbon nitride (CdS/g-C3N4) with different ratios of CdS were prepared. The CdS/g-C3N4 composite photocatalysts were characterized in detail and their photocatalytic activity was evaluated by using rhodamine B and colorless metronidazole as probes. Compared with pure g-C3N4, the CdS/ g-C3N4 composite exhibits significantly enhanced photocatalytic activity under visible-light irradiation. More importantly, g-C3N4 substantially reinforces the photostability of CdS nanowires even in a nonsacrificial system. The synergistic effect between CdS and g-C3N4 is found to be primarily responsible for enhancement of the separation of photogenerated electrons and holes, which helps improve the photocatalytic performance. A probable photodegradation process of metronidazole was proposed based on an analysis of the degradation products. This study provides new insight into the preparation of highly efficient and stable sulfidebased composite photocatalysts and facilitates their application in a number of environmentally sensitive areas. [ABSTRACT FROM AUTHOR]

The fast development of the design, construction, and application of metal-organic materials including infinite metal-organic frameworks (MOFs) and discrete metal-organic cages (MOCs) has not only propelled the advance of modern supramolecular syntheses to an unprecedented level, but also burgeoned various kinds of detection and characterization technologies. Herein, complementary techniques, including di-versified NMR and ESI-MS spectrometry, solid-state crystallography, and theoretical simulation are exploited to elucidate the structural evolution of a dynamic supramolecular coordination system involving PdII-MOCs of different compositions. The combination of various kinds of modern techniques verifies the anion template effect, which leads to the preferred formation and further conversion of Pd2L4 and Pd3L6 cages. [ABSTRACT FROM AUTHOR]

Octadecahedral α-Fe2O3 nanoparticles were hydrothermally synthesized in the presence of formamide. These octadecahedral α-Fe2O3 nanoparticles have a threefold axis and are enclosed by twelve dominant {112} facets and six {104} facets. In comparison with the {104} facets, the sterically less hindered {112} facets induced the selective adsorption of formamide more easily, which resulted in the gradual increase in the amount of {112} facets by decreasing the amount of {104} facets with increasing formamide. The coercivity ( Hc) of these octadecahedral particles increased successively as the aspect ratio ( c/ a) increased. The sensing capability of these particles toward H2O2 was investigated, and the response currents of the particles dominated by {112} facets showed a linear relationship with a concentration of H2O2 in the range from 40 μ M to 6.66 m M in different stages. [ABSTRACT FROM AUTHOR]