Ligand substitution at a hexa-coordinate centre. Reaction of Co2(Et2dtc)5] BF4 with some dithio-oxamides. Part II. A kinetic study
作者:Paola Deplano、Emanuele F. Trogu
DOI:10.1016/s0020-1693(00)89151-3
日期:1982.1
The reaction [Co2(Et2dtc)5] BF4 + DTO → [Co(Et2dtc)2DTO] BF4 + Co(Et2dtc)3 (where Et2dtc= N,N-diethyldithiocarbamate and DTO = substituted dithio-oxamides as N,N,N′,N′-tetraethydithio-oxamide = Et4DTO; N,N′-diisopropyldithio-oxamide = Pr2DTOH2; N,N′-difurfuryldithio-oxamide = Fur2DTOH2; N,N′-dimorpholyldithio-oxamide = Mo2DTOH2) was followed spectrophotometrically in CH2Cl2 medium. The kinetic expression
反应[Co2(Et2dtc)5] BF4 + DTO→[Co(Et2dtc)2DTO] BF4 + Co(Et2dtc)3(其中Et2dtc = N,N-二乙基二硫代氨基甲酸酯,DTO =取代的二硫代乙酰胺为N,N,N' N,N'-四乙基二硫代草酰胺= Et4DTO; N,N'-二异丙基二硫代草酰胺= Pr2DTOH2; N,N'-二糠基二硫代草酰胺= Fur2DTOH2; N,N'-二吗啉基二硫代草酰胺= Mo2DTOH2)分光光度法。该反应的动力学表达式是一个二阶速率定律,伪一级速率常数服从以下表达式:Kobs = K1 + KII [DTO]其中kII⪢kI并取决于配体的性质。在速率确定步骤之前,调用一种机制,该机制涉及Co(Et2dtc)3单元的单端可逆解离。对速率定律(kII)的二阶贡献与传入配体的亲核参与有关。kI术语也可能与双分子过程有关,即Co(Et2dtc)3的置换,一端