Kinetics of zinc-glycine interactions in aqueous solution
Kinetics of zinc-glycine interactions in aqueous solution
复制标题
水溶液中锌-甘氨酸相互作用的动力学
DOI：
10.1021/ic50117a037
复制
发表时间：
1972
影响因子：
4.6
通讯作者：
J. Stuehr
中科院分区：
文献类型：
--
作者：
J. Miceli;J. Stuehr
用跳温光谱法测定了锌-甘氨酸水溶液体系在毫秒时间范围内的两个浓度和pH值相关的弛豫时间。在稀溶液中测量速度越快。锌与游离甘氨酸阴离子反应生成单甘酸盐络合物。在25和I= 0.1 M时，总的二级速率常数为1.5 × 10s M~ 1s -1。只有在浓甘氨酸溶液中才观察到较慢的时间，这是由于双甘氨酸复合物的形成伴随着速率决定的单分子重排。后者的速率常数估计为93秒-1。结构变化假定为四面体-*·八面体。
Two concentration and pH dependent relaxation times in the millisecond time region have been observed for the aqueous zinc-glycine system by means of temperature-jump spectrometry. The faster of the times was measured in dilute solutions. The process responsible was shown to be theformation of the monoglycinate complex from the reaction of zinc with free glycine anion. The overall second-orderrate constant is 1.5 X 10s M~ l sec-1 at 25 and I= 0.1 M. The slower time, observed only in concentrated glycine solutions, was attributed to the formation of the bis glycinato complex accompanied by a rate-determining unimolecular rearrangement. The rate constant for the latter was estimated to be 93 sec-1. The structure change is postulated to be tetrahedral-*· octahedral.