Synthesis, Structure Evaluation, Spectroscopic and Antibacterial Investigation of Metal Complexes with 2-(Pyridin-4-yl)quinoline-4-carboxylic Acid.

Four metal complexes based on quinoline carboxylate ligand from 2-(pyridin-4-yl)quinoline-4-carboxylic acid (HL), [ML2(H2O)2] · 2H2On (M = MnII, 1; M = CoII, 2; M = CdII, 3) and [Ag2L2(H2O)2] · 3H2On (4) have been synthesized under hydrothermal conditions. Their structures were determined by elemental analyses, IR spectra, and further characterized by single-crystal X-ray diffraction analysis. Complexes 1-3 feature a 1D chain structure which is further linked together to construct the 3D supramolecular network through hydrogen bonds. Complex 4 exhibits a 3D configuration. The fluorescent behavior and antibacterial activities of these compounds have been investigated.

[Distribution and Fluxes of Perfluoroalkyl and Polyfluoroalkyl Substances in the Middle Reaches of the Yellow River (Weinan-Zhengzhou Section)].

Surface water samples were collected in the middle reaches of the Yellow River (Weinan-Zhengzhou section) and all 28 perfluoroalkyl and polyfluoroalkyl substance (PFAS) levels were measured using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results show that the levels of PFASs in the water and particle phase are 18.4-56.9 ng·L-1 and 26.8-164 ng·g-1, respectively. Perfluorohexanoic acid (PFHxA) in the water and particle phases is the main pollutant, accounting for 27% and 16% of the total concentrations, respectively, and 3H-perfluoro-3-[(3-methoxy-propoxy)-propanoate] acid (ADONA) and chlorinated polyfluorinated ethersulfonic acids (6:2 and 8:2 Cl-PFESA) were detected in the particle phase, indicating that the use of PFAS alternatives gradually increases. The lgKd of PFASs between the water and particle phase ranges from 2.95±0.553 (PFPeA) to 3.85±0.237 (8:2 FTUCA)and the adsorption of fluorotelomer carboxylic acids (FTCAs) and fluorotelomer unsaturated carboxylic acids (FTUCAs) on particulate matter increases with increasing of carbon chain length. Perfluoroalkane sulfonic acids (PFSAs) are more easily adsorbed by particulate matter than perfluoroalkyl carboxylic acids (PFCAs). The fluxes of PFASs in the Weinan-Zhengzhou section of the Yellow River show a decrease at first and then increase, indicating that this section receives pollution inputs from the upstream and tributaries. In addition, the results show that the fluxes of PFASs in the water phase are greater than those in the particle phase.