A highly selective compound for lead: Complexation studies of decamethylcucurbit[5]uril with metal ions

被引：74

作者：

Zhang, XX ^{[1
]}

Krakowiak, KE ^{[1
]}

Xue, GP ^{[1
]}

Bradshaw, JS ^{[1
]}

Izatt, RM ^{[1
]}

机构：

[1] Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA

来源：

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH | 2000年 / 39卷 / 10期

关键词：

D O I：

10.1021/ie0001725

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

Calorimetric and potentiometric studies indicate that a cage-type compound, decamethylcucurbit[5]uril (MC5), shows very high selectivity for Pb2+ over alkali, alkaline-earth, NH4+, and Cd2+ cations. The selectivity factor is > 10(5.5), Thermodynamic quantities (log K, Delta H, and Delta S values) for the interactions of MC5 with metal ions were determined at 25 degrees C by calorimetric titration in 50% formic acid/water (v/v) and by potentiometric titration in an aqueous solution. The log K(H2O) value for protonation of MC5 was determined to be 9.56. Pb2+ forms both 1:1 and 2:1 (Pb2+/MC5) complexes in 50% formic acid/water and aqueous solutions, while all other cations studied form only 1:1 complexes with MC5 in the 50% formic acid/water solution. However, both 1:1 and 2:1 complexes have been detected in an aqueous solution for Sr2+, indicating that the stoichiometry of MC5 complexes in 50% formic acid and in aqueous solutions could be different.

引用

页码：3516 / 3520

页数：5