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1

Poly(vinyl chloride)-supported triazoles grafted onto calix[4]arene for chromium ions extraction

Said Ammar, Dardouri Mokhtar, Ammari Fayçel, Ouerghui Abid, Power Nicholas P., Meganem Faouzi

Polimery

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2021

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T. 66, nr 11-12

611--618

EN

A new suitable material was synthesized using click reaction between dialkynyl-p-tert-butylcalix[4]arene and poly(vinyl chloride) azide (PVC-N3 ). This novel dialkynyl-p-tert-butylcalix[4]arene with triazole groups grafted onto PVC polymer (PVC-0.75CX[4]) has an excellent extraction capability for chromium ions from aqueous solutions. It shows a unique ability to extract chromium (VI) ions from aqueous solutions, thanks to the soft cavity, the presence of π-triazole rings and hydrogen bonds. Cr (VI) ion sorption capacity is 95.5% at pH = 3.

PL

W wyniku reakcji typu click między dialkynylo-p-tert-butylokaliks[4]arenem a azydkiem poli(chlorku winylu) (PVC-N3 ) otrzymano nowy związek − dialykynylo-p-tert-butylokaliks[4]aren z grupami triazolowymi szczepiony na poli(chlorku winylu) (PVC-0.75CX[4]). Wykazuje on wyjątkową zdolność do ekstrakcji jonów chromu(VI) z roztworów wodnych, dzięki sprężystej wnęce, obecności pierścieni π-triazolowych i wiązań wodorowych. Zdolność do sorpcji jonów Cr(VI) wynosi 95,5% przy pH = 3.

2

NMR Evidence for Protonated Tetraethyl p-tert-Butylcalix[4]arene Tetraacetate

Kriz J., Dybal J., Makrlik E., Vanura P.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 7

1321-1326

EN

In addition to well-known complexes of tetraethyl p-tert-butylcalix[4]arene tetraacetate (abbrev. 1) with alkali metal cations, an equimolar complex of this compound with H3O+, i.e. 1źH3O+, was found to be formed slowly in acetonitrile, however, with a very high equilibrium constant, the value ofwhich is beyond the possibilities of exact determination by NMR. Hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) was used as a proton source. Further, by a combination of 1D and 2D 1H NMR with 13C NMR spectra, it was proved that the ester carbonyls of 1 are not strongly involved in coordination of H3O+. It means that the most probable structure of the 1źH3O+ complex is obviously that with H3O+ bound by strong hydrogen bonds to the phenoxy oxygen atoms of 1.

3

Ion binding properties of 5,11,17,23-tetra-tert-Butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-bis(diphenylphosphinoylmethoxy)calix[4]arene towards alkaline-earth cations

Yaftian M. R., Abdollahi H., Shokouhi R., Tavakoli M., Matt D.

Chemia Analityczna

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2007

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Vol. 52, No. 1

103-113

EN

The ability of 5,11,17,23-tetra-tert-butyI-25,27-bis(diethylcarbamoylmethoxy)-26.2S-bis(dipheny]phosphinoy[methoxy)calix[4]arene (calix-1) to complex alkaline-earth ions was evaluated by determination of stability constant of respective complexes in methanol and mixed methanol-X solvents (X = acetonitrile or tetrahydrofuran) at 20°C by UV-VIS spec-troscopy. The analysis of the obtained spectra has shown a 1:2 (calix-1/metal) stoichiomet-ric ratio for Ca2 and S2+ complexes, and 1:1 stoichiometry-for Ba2+ in all studied solvents. An addition of either acetonitrile or tetrahydrofuran to methano! increased stability of M-ca!ix-l (M - an alkaline-earth ion) complexes. The results have shown a significantly greater affinity of calix-1 receptor towards calcium ion than to other alkaline-earth ions. To demonstrate analytical applications of the studied calixarene, it has been used as an ionophore in a new PVC coated graphite membrane of Ca2+-selective electrode. The membrane comprised 6% calix-I. 61% solvent mediator {ortho-nitrophenyloctyI ether).30% PVC, and 3% anion excluder (sodium tetraphenylboratc). The electrode exhibited a near-Nernstian response of 30.7 š 0.2 mV/decade over a concentration range of calcium ion of 1 x 10-5- 1 x 10-3 mol L-3 , detection limit was 3.6 x 10-6 mol L-1 . The working pH range of the proposed electrode was 4-7. The electrode was successfully used as a potentiometric sensor in complexometric titration of calcium ion in various solutions.

PL

Oceniono zdolność 5.11,17.23-tetra-fórt-bulyl-25,27-bis(dietyIokarbamoilmetoksy)-26.28--bis(difenylofbsfinoilrnetoksy)kaliks[4]arenu (calix-1) do wiązania w kompleks jonów metali ziem alkalicznych na drodze wyznaczenia stałych wartości odpowiednich kompleksów w metanolu i rozpuszczalnikach mieszanych: metanol-X {X = acetonitryl lub tetrahydrofu-ran), za pomocą spektroskopii UV-VIS w 20°C. Analiza uzyskanych widm wykazała, że stechiometria kompleksów (calix-1—metal) wynosi l :2 dla Ca<2+ i Sr2+ oraz l: l dla Ba;2+ we wszystkich badanych rozpuszczalnikach. Dodatek acetonitrylu lub tetrahydrofuranu do metanolu zwiększa trwałość kompleksów: M-calix-1 (M -jon metalu ziem alkalicznych). Wyniki wskazują na dużo większe powinowactwo receptora calix-1 w stosunku do wapnia niż w stosunku do pozostałych metali ziem alkalicznych. W celu wykazania analitycznych zastosowań badanego kaliksarenu użyto go w charakterze jonoforu w nowej, selektywnej względem Ca2+ elektrodzie z membrana PVC na graficie. Membrana składała się z 6% eteru o-nitrofenylooktyiowego jako mediatora. 30% PVC i 3% tetrafenyloboranu sodu. Elektroda ta wykazywała nieomal Ncrnstowską odpowiedź 30,7 š 0,2 niV/dekadę w zakresie stężeń jonu wapniowego: l x 10-5 x 10-1mol L-1.Roboczy zakres pH nowej elektrody wynosił 4-7. Elektrodę zastosowano z powodzeniem w charakterze potencjometrycznego sensora w kompleksometrycznyrn miareczkowaniu jonów wapniowych w różnych roztworach.

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Extractive separation of rare earth ions by using calix[4]arene with isopropyl hydrogen phosphonate at upper rim

Ohto K., Yamasaki T., Inoue K.

Ars Separatoria Acta

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2006

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No. 4

96-106

EN

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.

5

Silver ion selective electrode based on (2-pyridylmethoxy)-p-t-octylcalix[4]arene

Higuchi H., Shinohara T., Oshima T., Ohto K., Inoue K.

Ars Separatoria Acta

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2002

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No. 1

99-103

EN

Calix[4]arene bearing pyridyl group at lower-rim has been used as an ionophore for silver ion-selective electrode. The electrode membranes containing different amount of potassium tetrakis(p-chlorophenyl)borate (KTpClPB) were prepared to investigate the influence of KTpClPB on potential response. The response behavior for membranes depends on the amount of KTpClPB and dramatically changes from anion to cation response. The membrane containing 135 mol % with respect to ionophore gives linear response to Ag+ in the concentration range from 10-5.5 to 10-2 M AgNO3.

6

Effect of coexisting sodium ion extractive separation of metal ions with calix[4]arene tetracarboxylic acid

Ohto K., Shioya A., Higuchi H., Oshima T., Inoue K.

Ars Separatoria Acta

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2002

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No. 1

61-70

EN

Solvent extraction of metal ions with calix[4]arene tetracarboxylic acid has been carried out to elucidate effect of coexisting sodium ion. Extraction of metal ions examined, Pb(II), Fe(III), Cu(II), Zn(II), Ni(II), and Co(II), is enhanced by the addition of sodium ion. The enhancement degree of the metal extraction is not necessarily in proportion to the added sodium concentration. The addition of trace amount of sodium ion is necessary to specifically complex for calix[4]arene tetracarboxylic acid and to enhance the extraction ability. However, the addition of excessive amounts of sodium suppresses the extraction of other metal ions, since they act as a competitive ion with other metal ions; The relation between extractive pH1/2 of metal ions and sodium concentration is shown. Mutual separation of metal ions by using additional sodium ion is also investigated. Although complete mutual separation of three metal ions, Pb(II), Cu(II), and Zn(II), has not been achieved, the possibility that the sodium addition will enhance not only the extraction ability but also the separation efficiency is suggested.