1-(2-Pyridylazo)-2-napthol (hereafter 1Q) is widely used as a chelating ligand applied in chelatometric, spectrophotometric analysis of metal ions. It appeared from the literature survey that no inclusion complex of 1Q was reported with nitroaromatics. The formation of charge-transfer complex gives an opportunity to improve the physico-chemical properties of different donors. So the complex of 1Q with 4-nitrophenol (4-NP), 2,4-dinitrophenol (2,4-DNP), picric acid (PA), and 3,5-dinitrosalicylic acid (3,5-DNSA) was described in this work in methanol medium. The ground and excited state binding constants and other spectroscopic data have been determined using UV-vis and fluorescence spectroscopic studies. All the complexes have been synthesized and characterized using FT-IR, H NMR, and elemental analysis. Spectroscopic data reveal that 1Q joins by a NHO type hydrogen bond with nitroaromatics. Job's plot of the continuous variation of absorbance indicates that stoichiometry of CT-complex was 1:1. Thermal stability of the synthesized complex has determined by TGA-DTA analysis. Energy-minimization DFT calculation further supported the formation of the H-bonded charge-transfer adduct.
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http://dx.doi.org/10.1016/j.saa.2017.01.047 | DOI Listing |
J Phys Chem A
January 2025
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
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View Article and Find Full Text PDFSci Rep
January 2025
Laboratory for Radiophysical and Optical Methods of Environmental Research, National Research Tomsk State University, Tomsk, Russia, 634050.
Monitoring the parameters and behavior of plankton makes it possible to assess the state of the aquatic ecosystem and detect the beginning of an environmental disaster at an early stage. In this respect, the most informative method for the in situ plankton study is underwater digital holography. This method allows obtaining information on the size, shape, and location of plankton individuals, as well as performing their classification and biotesting according to their behavioral responses using a submersible holographic camera non-invasively, in real time, and in the automatic mode.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
December 2024
Engineering Research Center for Industrialization of Southern Medicinal Plants Resources of Hainan Province, Hainan Normal University Haikou 571158, China Key Laboratory of Southern Medicinal Plants Resources of Haikou City, Hainan Normal University Haikou 571158, China Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Hainan Normal University Haikou 571158, China.
The chemical constituents from the stems and leaves of Mycetia hainanensis were isolated by silica gel, ODS gel, and Sephadex LH-20 gel column chromatography and preparative HPLC. The chemical structures of all the isolated compounds were identified on the basis of their physicochemical properties, spectroscopic data, as well as the comparison of their physicochemical and spectroscopic data with the reported data in literature. Twelve compounds were isolated from the 85% ethanol extract of the stems and leaves of M.
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National Center for Screening New Microbial Drugs, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, PR China. Electronic address:
Two cyclic octadepsipeptides, microascusins A and B (1 and 2), were identified from the marine sponge-associated Microascus croci IMB19-064 co-cultivated with Escherichia coli. Their structures and conformations in solution were determined by comprehensive spectroscopic data analysis. The absolute configurations of amino and hydroxy acids were determined by the advanced Marfey's and O-Marfey's methods, respectively, as well as chiral-phase HPLC analysis.
View Article and Find Full Text PDFJ Nat Prod
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Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry and Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
A chemical investigation of the soil-derived fungus sp. XZ8 led to the isolation of five new indole alkaloids, trichindoles A-E (-), with diverse architectures, along with seven known analogues (-). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by single-crystal X-ray diffraction and modified Mosher's method.
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