Temat: ethers - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Application of macrocycle compounds for metal ions separation and removal - a review
Autorzy:: Walkowiak, W.
Ulewicz, M.
Kozłowski, C. A.
Powiązania:: https://bibliotekanauki.pl/articles/346971.pdf
Data publikacji:: 2002
Wydawca:: Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:: macrocycles
crown ethers
lariat ethers
metal ions
separation
Opis:: A review is presented on macrocyclic compounds novel reagents for metal ions separation and removal in solvent extraction, transport through liquid membranes, and flotation processes. As macrocyclic compounds were used such chemicals as non-ionizable crown ethers, ionizable crown ethers (lariat ethers), calixarenes, and acyclic polyethers. Many literature data as well our own recent research data will be reported on metal ions removal and separation.
Źródło:: Ars Separatoria Acta; 2002, 1; 87-98
1731-6340
Pojawia się w:: Ars Separatoria Acta
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The effect of benzene moiety fused with macrocyclic ring on the proton affinity of crown ethers studied in MS/MS experiment
Autorzy:: Frański, R.
Gierczyk, B.
Powiązania:: https://bibliotekanauki.pl/articles/346947.pdf
Data publikacji:: 2008
Wydawca:: Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:: crown ethers
proton affinity
mass spectrometry
Opis:: In this paper we address the question how the presence of an aromatic moiety affects the proton affinity of crown ethers. In order to compare the proton affinities of crown ethers studied (M), we compared the abundances of protonated crown ethers ([M + H]+ ions) with the abundance of the ion [NH2-B15C5 + H]+ (formally also protonated crown ether). Both [M + H]+ and [NH2-B15C5 + H]+ were formed as a result of decomposition of [NH2-B15C5 + H + M]+. The presence of a benzene moiety fused with a macrocyclic ring strongly decreases the ratio [M + H]+/[NH2-B15C5 + H]+. Thus, the higher ring strain caused by the benzene moiety leads to a substantial lowering of the proton affinity of crown ethers. It is also suggested that for protonated benzocrown ethers the ring strain is partly compensated by the proton-đ interaction. The presence of an NO2 group decreases the electron density on the aromatic ring and, consequently, the proton-đ interaction is suppressed. As expected, the proton affinity of benzo-crown ethers increases with increasing size of their cavity since the ring strain is lower for larger molecules. An unexpectedly high proton affinity of dicyclohexano-18-crown-6 (DC18C6) has been observed.
Źródło:: Ars Separatoria Acta; 2008, 6; 61-68
1731-6340
Pojawia się w:: Ars Separatoria Acta
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Proton - ionizable lariat ethers in ion flotation process - effect of alkali metal cations
Autorzy:: Ulewicz, M.
Maciejewski, P.
Powiązania:: https://bibliotekanauki.pl/articles/346941.pdf
Data publikacji:: 2008
Wydawca:: Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:: ion flotation
crown ethers
cesium(I)
barium(II)
Opis:: An experimental investigation is presented on flotation of Cs+, Sr2+ and Ba2+ cation metals from dilute aqueous solutions using lariat ethers with a novel protonionizable group in the presence of foaming agent. The influence of concentration of Li+, Na+, K+ (as source of foreign cations) on kinetic rate constant and maximal percent removal was studied. The addition of Li+, Na+, K+ cations (over 1.0ź10-3 mol/dm3) depressed the removal of Cs+, Sr2+ and Ba2+ remarkably, and the removal of floated cations was very low (at the concentration of alkali metal cations – 1.0ź10-2 mol/dm3). The influence of foreign cations on flotation depression increases in the order: K+ < Li+ < Na+. Authors propose the correlation between the maximal percent removal of Cs+, Sr2+ or Ba2+ and concentration of Li+, Na+ or K+ cations in aqueous solution.
Źródło:: Ars Separatoria Acta; 2008, 6; 53-60
1731-6340
Pojawia się w:: Ars Separatoria Acta
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: N-(diethylthiophosphoryl)-aza[18]crown-6: synthesis and ability of solvent extraction toward lead(II), zinc(II) and cadmium(II) metal cations
Autorzy:: Kozlowska, J.
Miroshnichenko, S.
Powiązania:: https://bibliotekanauki.pl/articles/346955.pdf
Data publikacji:: 2013
Wydawca:: Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:: crown ethers
solvent extraction
lead(II)
zinc(II)
cadmium(II)
Opis:: This work presents the synthesis of a strongly hydrophobic, functionalized monaza crown ether, i.e., lariat ether, namely N-(diethylthiophosphoryl)-aza[18]crown-6 and its application as ion extractant in solvent extraction systems. The synthesis of thiophosphorylated aza[18]crown-6 was performed with good yield. Separation systems have been successfully developed to extract Pb(II), Cd(II) and Zn(II) into organic phase, i.e., chloroform with the crown ethers: aza[18]crown-6 and N-(diethylthiophosphoryl)-aza[18] crown-6 as extractants. The selectivity order in both crown ethers was Pb(II) >> Cd(II) > Zn(II). The obtained results suggest that N-(diethylthiophosphoryl)-aza[18]crown-6 can be used for the selective removal of Pb(II) at lower pH values than aza[18]crown-6.
Źródło:: Ars Separatoria Acta; 2012-2013, 9/10; 7-14
1731-6340
Pojawia się w:: Ars Separatoria Acta
Dostawca treści:: Biblioteka Nauki

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