Di-ionizable p-tert-butylcalix[4]arene-1,2-crown-5 ligands in the cone conformation: effect of acidic side arm length for solvent extraction of divalent metal ions

TETRAHEDRON

卷:71

Article

Yang, Yanfei¹  Lee, Eun Kyung¹  Surowiec, Kazimierz¹  Bartsch, Richard A.¹ 

[1] Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA

关键词: Calixarenes;    Proton-ionizable ligand;    Selective binding;    Solvent extraction;   

DOI  :  10.1016/j.tet.2014.11.042

来源: Elsevier

【 摘 要 】

Several new di-ionizable p-tert-butylcalix[4]arene-1,2-crown-5 compounds were prepared in the cone conformation. For comparison with reported ligands, the systematic structural variation was a change of the pendent acidic groups from two adjacent -OCH2CO2H or -OCH2C(O)NHSO(2)Z (with Z=-Me, -Ph, -C6H4-4-NO2, -CF3) units to two adjacent -O(CH2)(4)CO2H or -O(CH2)(4)C(O)NHSO(2)Z groups. Competitive solvent extractions of alkaline earth metal (AEMC) cations from aqueous solutions into chloroform by these ligands were performed. Also single species solvent extractions were conducted for the divalent heavy metal cations of Pb2+ and Hg2+. Comparison of the extraction data for the new ligands with those reported reveal that the ligands with shorter proton-ionizable side arms are more effective divalent metal ion extractants. (C) 2014 Elsevier Ltd. All rights reserved.

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