Abstract :
A study of the complexation of heavy metal ions by the coronands 3,12,20,29-tetraoxa-35,36-diazapentacyclo[29.3.1.1.14,18.05,10.022,27]-hexatriaconta-1(35),5(10),6,8,14,16,18(36),22(27),23,25,31,33-dodecaene (1); 2,3,11,12-bis (4′-methylbenzo)-1,4,10,13-tetrathia-7,16-dioxacyclo-octadeca-2,11-diene (2); 7,16-diaza-1,4,10,13-tetraoxa-2,3,11,12-dibenzocyclooctadeca-2,11-diene (3); 2-[19-(2-hydroxy-2-phenylethyl)-7,8,9,10, 18,19,20,21-octahydro-6H,17H-dibenzo[b,k][1,4,10,13,7,16]tetraoxadiazacyclooctadecin-8-yl]-1-phenyl-1-ethanol (4); 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane (5); and 2-[16-(2-hydroxy-2-phenylethyl)-1,4,10,13-tetraoxa-7,16-diazacyclo-octadecanyl]-1-phenyl-1-ethanol (6) is described. Coronands 1 and 3 were prepared by literature methods, improved methods were used to prepare 2, and 4 and 6 were prepared from 3 and 5 (obtained commercially), respectively. Potentiometric studies in N,N-dimethylformamide yielded (logK/dm3 mol−1)=5.50, 6.49, 9.42 and 7.52 for [Ag · 1]+, [Ag · 2]+, [Ag · 5]+ and [Ag · 6]+, respectively; <2, <2, 4.30 and <2 for [Zn · 1]2+, [Zn · 2]2+, [Zn · 5]2+ and [Zn · 6]2+, respectively, <2, <2, 5.92 and >7.52 for [Cd · 1]2+, [Cd · 2]2+, [Cd · 5]2+, and [Cd · 6]2+, respectively, and 2.62, 2.38, 6.71 and >7.52 for [Pb · 1]2+, [Pb · 2]2+, [Pb · 5]2+, and [Pb · 6]2+, respectively. ESI-MS studies of the interactions of 1–6 with Ag+, Zn2+, Cd2+ and Pb2+ are also reported.
