在酸性至碱性溶液中，紫外线I与1-羟基乙烷-1,1-二膦酸的络合作用。

Complexation of UVI with 1-hydroxyethane-1,1-diphosphonic acid in acidic to basic solutions.

作者信息

Reed Wendy A, Rao Linfeng, Zanonato PierLuigi, Garnov Alexander Yu, Powell Brian A, Nash Kenneth L

机构信息

Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.

出版信息

Inorg Chem. 2007 Apr 2;46(7):2870-6. doi: 10.1021/ic0621401. Epub 2007 Mar 7.

DOI:10.1021/ic0621401

PMID:17341063

Abstract

Complexation of UVI with 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) in acidic to basic solutions has been studied with multiple techniques. A number of 1:1 (UO2H3L), 1:2 (UO2HjL2 where j = +4, +3, +2, +1, 0, and -1), and 2:2 [(UO2)2HjL2 where j = +1, 0, and -1] complexes form, but the 1:2 complexes are the major species in a wide pH range. Thermodynamic parameters (formation constants and enthalpy and entropy of complexation) were determined by potentiometry and calorimetry. Data indicate that the complexation of UVI with HEDPA is exothermic, favored by the enthalpy of complexation. This is in contrast to the complexation of UVI with dicarboxylic acids in which the enthalpy term usually is unfavorable. Results from electrospray ionization mass spectrometry and 31P NMR have confirmed the presence of 1:1, 1:2, and 2:2 UVIHEDPA complexes.

摘要

已采用多种技术研究了在酸性至碱性溶液中铀酰离子（UVI）与1-羟基乙烷-1,1-二膦酸（HEDPA）的络合作用。形成了多种1:1（UO₂H₃L）、1:2（UO₂HjL₂，其中j = +4、+3、+2、+1、0和 -1）以及2:2 [（UO₂）₂HjL₂，其中j = +1、0和 -1] 络合物，但1:2络合物是在较宽pH范围内的主要物种。通过电位滴定法和量热法测定了热力学参数（形成常数以及络合的焓和熵）。数据表明，UVI与HEDPA的络合是放热的，受络合焓的影响。这与UVI与二羧酸的络合情况相反，在二羧酸络合中焓项通常是不利的。电喷雾电离质谱和³¹P NMR的结果证实了1:1、1:2和2:2 UVI-HEDPA络合物的存在。