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Wyszukujesz frazę "phosphonate" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Extractive separation of rare earth ions by using calix[4]arene with isopropyl hydrogen phosphonate at upper rim
Autorzy:
Ohto, K.
Yamasaki, T.
Inoue, K.
Tematy:
calix[4]arene
phosphonate
rare earth ions
extraction
selectivity
Pokaż więcej
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Powiązania:
https://bibliotekanauki.pl/articles/346933.pdf  Link otwiera się w nowym oknie
Opis:
5,11,17,23-Tetrakis(isopropyl hydrogen phosphonomethyl)- 25,26,27,28 - tetrapropoxycalix[4]arene in cone conformation has been synthesized to investigate extraction behavior for nine trivalent rare earth metal ions from chloride media into chloroform, together with isopropyl hydrogen (4-propoxyphenyl)methylphosphonate as a corresponding monomer. Although the aqueous distributions of the present extractants were greater than those of butyl ester type of the previous extractants, they were trace and slight amounts under the experimental condition for calix[4]arene and monomeric derivatives, respectively. From the result of pH dependency, extraction takes place by a simple ion-exchange mechanism for both extractants. The extraction ability between the present extractants for rare earth ions was comparable. Results of a Job plot and a loading test indicate that for calix[4]arene derivative, stoichiometry of the extraction is 1:1. The separation efficiency of a calix[4]arene derivative is less than that of a monomeric derivative. It is attributed to the offset by the size effect of a coordination site at the larger upper rim of calix[4]arene (for relatively larger light rare earth ions) and strong affinity of phosphonate group to heavy rare earth ions. Such result is similar to that of derivatives with butyl ester.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revealing the molecular structure of copper phosphonate groups anchored inside SBA-15 silica channels : theoretical and experimental study
Autorzy:
Doskocz, Marek
Laskowski, Łukasz
Walcarius, Alain
El Houbbadi, Sara
Laskowska, Magdalena
Olejniczak, Zbigniew
Maximenko, Alexey
Opis:
This study aims to thoroughly understand the local structure of copper phosphonate groups covalently attached via propyl arms to pores interior of SBA-15 mesoporous silica. The studied sample contains 20% of propyl-POO2Cu groups attached to the mesoporous silica matrix as host material. X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) at the copper K-edge were utilized to discern the valence state and geometric arrangement of copper sites within the pores. Various machine learning techniques, including principal component analysis, K-means clustering, and neural networks, were applied to theoretically calculated XANES spectra. This facilitated our quantitative analysis of the experimental spectrum and the extension of the EXAFS equation fit to the second shell. Additional molecular structure analysis was performed based on Raman scattering supported by numerical simulations. Nuclear magnetic resonance aided in analyzing the silicon and phosphorus environment. Results indicate that copper atoms are coordinated by two phosphonate groups, forming a pseudo-bi-trigonal pyramid with surrounding oxygen atoms. These results contribute to a better understanding of the physical properties of the studied nanocomposite material. This, in turn, makes it possible to optimize the molecular structure of materials to optimize their antimicrobial and photonic properties, making them useful in practice.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
    Wyświetlanie 1-6 z 6

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