مرکز منطقه ای اطلاع رساني علوم و فناوري - Synthesis of Cyclic Calix-crown Derivatives and Using in the Phase-Transfer Reactions

Abstract :

This study comprises synthesis of calixcrown derivatives containing cyclic structure that are selective extractants for toxic metal cations and their liquid-liquid extraction studies. Structures of these compounds were characterized by spectroscopic techniques (FTIR, 1H NMR, MAS) and elemental analysis. Synthetic work was carried out according to the methods described in the literature. After the synthesis of 5,11,17,23-tetra-ter-butyl-25,26,27,28-tetra-hydroxycalix[4]arene (1) ter-butyl groups on the p-position were removed by treating this compound with phenol in toluene along with aluminum chloride. Then compound 3 was obtained by treating compound 2 with p-nitrobenzyl bromide in acetonitrile in the presence of K2CO3. Compound 4 and 5 were obtained by reacting with compound 3 with triethyleneglycol ditosylate and 1,8-diptosylate-3,6-dithiaoctane respectively with Cs2CO3 in dry acetonitrile. Then nitro groups of these compounds were reduced individually by treatment of these compounds with Raney-Ni in the mixture of ethylacetate and methanol along with hydrazine (6 and 7). The compound 6 and 7 were reacting with adipoylchloride along with pyridine in dry THF individually to obtain compound 8 and 9. To view the ion transport properties of these compounds liquid-liquid extraction studies were performed with alkali (Li^+ , Na^+ , K^+ and Cs^+) transition metal (Ni^2+, Co^2+, Cu^2+, Cd^2+ and Hg^2+ , Pb^2+) cations and Cr2O7= anion. From the extraction data it has been concluded that the compound 8 is selective against Na metal, while the compound 9 is selective, especially against Hg^2+ cation. Additionally It has been observed from the dichromate anion extraction studies that the compound 6 transported large amounts of Na2Cr2O7 from aqueous phase into the organic phase.