酸性媒介黄GG与［Coen_2（OH）（OH_2）］^（2＋）的取代反应动力学及反应机理  

Kinetics of the substitution reaction of Co(III)bis(ethylenediamine) complexes withsolochrome yellow GG

作　　者：赵一伟[1] 许君兴[1] 张华麟[1] 

机构地区：[1]复旦大学化学系

出　　处：《复旦学报（自然科学版）》1994年第1期11-16,共6页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金

摘　　要：用分光光度法研究ｃｉｓ－［Ｃｏｅｎ２（ＯＨ）（ＯＨ）２］（ＣｌＯ４）２（ｅｎ为乙二胺）与酸性媒介黄ＧＧ染料（２－羟基－５－［（４－苯磺酸基）偶氮基］苯甲酸）的取代反应动力学．用ｐＨ电位滴定法测定了［Ｃｏｅｎ２（ＯＨ）２］＋、［Ｃｏｅｎ２（ＯＨ）（ＯＨ２）］２＋６０℃时的加质子反应平衡常数．用分光光度法测得６０℃时染料的酸解离常数．６０℃离子强度为０．１ｍｏｌ／ｋｇＮａＣｌＯ４时，各络合质点与染料的反应活性顺序为［Ｃｏｅｎ２（ＯＨ）（ＯＨ２）］２＋＞［Ｃｏｅｎ２（ＯＨ）２］＋＞［Ｃｏｅｎ２（ＯＨ２）２］３＋．由表观速率常数ｋｏｂｓ与Ｃｏ（Ⅲ）络合物浓度的关系及反应活化参数西ΔＨ、ΔＳ可见，该取代反应是按ＳＮ２缔合机理进行的．The kinetics of the substitution reaction of complex species [ Co en2(OH2)]23+,[ Coen2(OH)(OH2)]2+,[Coen2(OH)2]+ with 5-(4-sulfo phenylazo) salicylic acid has been studied spectrophotometrically.The protonation constants of [Coen2(OH)(OH2)]2+ Co[en2(OH)(OH2)]2+,and the acid dissociation constant of the phenolic group of azo dye were determined with PH potentiometric titration and spectrophotometrically respectively at 60℃.The sequence of the reactivity of reaction at 60℃ with 0.1 mol/kg NaClO4 present is: [Coen2(OH)(OH2)]2+>[Coen2(OH)2]+>[Coen2 (OH)2]3+.The relationship of the kobs, with the concentration of Co(III) complex and the activation parameters ΔH,ΔS support the reaction ispassed through a SN2 associative route.

关 键 词：络合物 乙二胺 取代反应 钴 

分 类 号：O614.812[理学—无机化学]