BDBPH—Zn Mn Cd双核配合物的稳定常数及其形态研究

THE STABILITY OF DINUCLEAR COMPLEXES OF BDBPH-METALS(2:1) AND THE SPECIES DISTRIBUTION

目的 测定BDBPH—Zn、Mn、Cd双核配合物的稳定常数 ,分析不同 pH条件下各物种的存在形式及变化规律。方法 温度 2 5 .0± 0 .10℃、离子强度 0 .10 0mol/L、N2 保护下用NaOH标准溶液滴定大环配体BDBPH—金属离子 (1:2 )酸性溶液 ,滴定 pH范围 2～ 12 ,高精度酸度计记录pH值 ,BEST程序计算稳定常数 ,SPE和SPEPLOT程序绘制样品分布曲线。结果 BDBPH—金属配合物的稳定常数分别为 17.72 (LogKLZn2 ) ,11.5 8(LogKLMn2 ) ,14 .2 8(LogKLCd2 )。结论 配体BDBPH能够与金属离子 (Zn、Mn、Cd)形成稳定的双核配合物。

Objective To study the stability constants, and discuss the species distribution of the dinucleating complexes of BDBPH-metal in 1:2 systems. Methods The temperature was maintained at 25.0±0.1℃ and the ionic strength of the medium was maintained at 0.100M. The stability constants and the species distribution were determined with the program BEST, program SPE and SPEPLOT.Results The main stability constants are logK Zn 2L =12.21,logK Cd L =12.36,logK Mn 2L =7.99. The main species was dinuclear complexes with the protonated ligand, M 2L. Conclusion The ligand has strong tendency to form dinuclear complexes with Zn(II)?Cd(II) and Mn(II), as well as mononuclear complexes.