NEB与过渡金属元素二元配合物的pH电位法研究  

Studies on the binary complexes of some transition metals with NEB by potentiometry

作　　者：朱元成[1] 刘流[1] 吴集贵[2] 邓汝温[2] 

机构地区：[1]天水师范学院化学系,甘肃天水741000 [2]兰州大学化学化工学院,甘肃兰州730000

出　　处：《化学研究与应用》2002年第1期34-36,8,共4页Chemical Research and Application

摘　　要：用精密pH电位法测定了在甲醇 水混合溶剂中配体氨三乙氧基三苯甲酸 (NEB)质子化常数 (2 5℃ ,I =0 .2 0mol·L- 1 NaCl) ,讨论了溶剂对质子化常数的影响 ,结果表明溶剂对质子化常数的影响呈线性关系。测定了NEB与部分过渡金属M(Ⅱ) (M =Cd、Co、Ni、Cu及Zn)二元配合物的稳定常数 ,实验数据处理用程序MINIQUAD - 82和MIQUV完成。在二元体系中存在的配合物物种有 112、111、110及 2 10型 (M2 + ∶NEB3- ∶H+ ) ,并且 111及 110型配合物稳定常数的变化规律Cd(Ⅱ) <Co(Ⅱ) <Ni(Ⅱ) <Cu(Ⅱ) >Zn(Ⅱ)符合IrvingThe protonation constants of the ligand 2,2′,2″ nitrilotris(2,1 ethanediyloxy)tris benzoic aicd(NEB) and the stability constants of its transition metal M(Ⅱ)(M=Cd?Co?Ni?Cu and Zn) complexes were determined in methanol water mixture potentiometrically(25℃,I=0.20mol·L -1 NaCl).Computer program MAGEC?MINIQUAD 82 and MIQUV were used for calculation.The effect of methanol solvent on protonation constants was discussed.There are three or four types of binary complexes that have been ascertained as the models 112?111?110 and 210(M∶L∶H,L=deprotonated NEB,H=proton),the stability constants order of complexes 111 and 110 for metal ions,which was found to be Cd(Ⅱ)<Co(Ⅱ)<Ni(Ⅱ)<Cu(Ⅱ)>Zn(Ⅱ),having an Irving Williams order.

关 键 词：NEB 过渡金属 二元配合物 PH电位法 氨三乙氧基三苯甲酸 质子化常数 稳定常数 测定 

分 类 号：O641.4[理学—物理化学]