Hasalettin Deligöz

LIQUID-LIQUID EXTRACTION OF TRANSITION METAL CATIONS BY CALIXARENE-BASED CYCLIC LIGANDS

ABSTRACT The selective liquid-liquid extraction of various alkali and transition metal cations from the aqueous phase to the organic phase was carried out by using p-tert-butylcalix[4]arene (L1), p-tert-butylcalix[6]arene (L2), tetra-ethyl p-tert-butylcalix[4]arene-tetra-acetate (L3), tetra-methyl-p-tert-butyl-calix[4]arene-tetra-ketone (L4), calix[n]arenes (n=4 and 6) bearing oxime groups on the lower rim (L5, L6 ) and a polymeric calix[4]arene. It was found that compounds L5 and L6, showed selectivity towards Ag+, Hg+, Hg2+, Cu2+, and Cr33+ and the order of the extractability was Hg+>Hg2+>Ag+>Cu2+>Cr3+. The polymeric calix[4]arene (L8) was selective for Ag+, Hg+ and Hg2+, unlike its monomeric analog.

Synthesis of polymer-supported calix[4]arenes and selective extraction of Fe3+

Abstract Three polymeric calix[4]arenes were synthesized by reacting chloromethylated polystyrene with 25,26,27-tribenzoyloxy-28-hydroxy calix[4]arene (2a, 3a) and polyacryloyl chloride with 25,26,27,28-tetraacetoxy calix[4]arene (4a). After alkaline hydrolysis of the polymers, they were utilised for selective extraction of some transition metal cations from aqueous phase to organic phase. It was found that the polymeric calix[4]arenes were selective to extract Fe3+ from an aqueous solution which contained Cu2+, Ni2+, Co2+, and Fe3+ cations and it was observed that the polymer supported onto the lower rim calix[4]arene is a more efficient carrier of Fe3+ in the extraction process.

Selective extraction of Fe3+ cation by calixarene-based cyclic ligands

Abstract The selective liquid-liquid extraction of Fe3+ cation from the aqueous phase to the organic phase was carried out by using p-tert-butylcalix[4]arene [L1], ca-lix[4]arene [L2], p-nitro-calix[4]arene [L3], calix[4]arene p-sulfonic acid [L4], p-(diethylamino)methylcalixt4]arene [L5], tetramethyl-p-tert-butylcalix[4]arene tet-raketone [L6], 25,27-dimethyl-26,28-dihydroxy-p-tert-butylcalix[4]arene diketone [L7], calix[4]arene-bearing dioxime group on the lower rim [L8], and a monooxime [L9]. The effect of varying pH upon the extraction ability of calixarenes substituted with electron-donating and electron-withdrawing groups at their p-position was examined. Observed results were compared with those found for unsubstituted calix[4]arene.

Synthesis and Ion Binding Properties of a p-Keto-oxime and a vic-Dioxime Derivative of Calix[6]arene

Abstract A keto-oxime derivative of calix[6]arene was synthesized from 5,11,17,23,29,35-hexaacetyl-37,38,39,40,41,42-hexamethoxycalix[6]arene by oxidation of the CH3 group of the acetyl groups to isonitroso groups. The prepared compound was converted into its vic-dioxime derivative by treatment with NH2OH.HCl. The resulting ligands (2, 3) were treated with three transition metal salts (e.g., CuCl2.2H2O, NiCl2.6H2O or CoCl2.6H2O). While the Cu(II), Ni(II) and Co(II) complexes of the vic-dioxime derivative of calix[6]arene were obtained, only Co(II) gave a complex with the keto-oxime derivative of calix[6]arene. All the complexes have a metal-ligand ratio of 3:1. The Cu(II) and Ni(II) complexes of 3 are square-planar, while the Co(II) complex of both ligands are octahedral with water molecules as axial ligands.

Sodium Complexes of Two Polymeric Calix[4]arene Tetraesters

Abstract In this study new Na+-complexes of polymeric calix[4]arenes which have more than one calix[4]arene tetraester units were prepared. The complexes have a metal to ligand ratio of 1:1, for each calix[4]arene tetraesters unit. The newly prepared compounds were characterised on the basis of their 1H NMR, IR, UV-visible spectra as well as elemental analyses.

Synthesis and Metal Complexation of Avic-Dioxime Derivative of Calix [6] Arene

Abstract A vic-dioxime derivative of calix[6]arene was synthesized from anti-chloroglyoxime and 5,11,17,23,29,35-hexamino-37,38,39,40,41,42-hexamethoxy-calix [6] arene. The prepared compound has six vic-dioxime groups and its complexes have a metal-ligand ratio of 3:1. The Cu(II) and Ni(II) complexes of the ligand are square-planar, while the Co(II) complex is octahedral with water molecules as axial ligands.

Studies on Compounds of Uranium(M) with Two vic Dioxime Derivatives of Gilixi[4]Arene

Abstract Two new dioxouranium(VI) complexes have been synthesued horn two vicdiome compounds of calix[4]arene (L1H and L2H, prepared fiom 28-[(4-ammobenzyl)oxy]-25,26,27-tnbenzoyloxycaluc[4]arene and amphi-chloroglyome or amphi-dichloroglyoxlme) and dioxouranium(VI) ion The complexes, which have been charactenzed on the bass of elemental analyses molar conductances, and mfiared and demonic spectral studies, have the general formulas [UO2(L1)2 2H2O].2THF and [UO2(L2)2.2H2O]3THF The complexes have a metal-ligand rabo of 1:2 and U(VI) has the coordinanon number of eight in both complexes

Synthesis and Metal Complexation of Two vic-Dioxime Derivatives of Calix[4]Arenes

Abstract Two new vic-dioxime compounds of calix[4]arene and their transition metal complexes were synthesized from 28-[(4-aminobenzyl)oxy]-25,26,27-tribenzoyl-oxycalix[4]arene and amphi-chloroglyoxime or amphi-dichloroglyoxime. The complexes of these compounds with Ni(II), Cu(II) and Co(II) ions were investigated. All of the complexes of these ligands are tetrahedral with a metal-ligand ratio of 1:2. The prepared compounds were characterised based on 1H NMR and IR spectra as well as elemental analyses.

Investigation of the Formation of Humic Acids from Lignite by Using Model Compounds

Abstract By using model compounds, the formation of humic acids from lignite was investigated. Quinones (p-benzoquinone, o-benzoquinone, p-toluquinone, 1,4-nafto-quinone, 9,10-anthraquinone, 9,10-phenanthraquinone), polyhydroxyaromatic compounds (1,2-dihydroxybenzene, 1,4-dihydroxybenzene), and hydroquinone-formalde-hyde resins were used as model compounds. Humic acids were obtained from all of the model compounds used except 9,10-anthraquinone. It was suggested that the formation mechanism of humic acids from lignite was similar to quinone-humic acids.