(μ-烯丙基硫)(μ-苯基硫)六碳基二铁亲核取代反应动力学的研究

A Study on the Kinetics and Mechanism of Nucleophilic Substitution Reaction ofμ-Allylthio-μ-Phenylthio-Bis(Tricarbonyliron)

一、实验部分1.药品配合物Fe_(2)(CO)6(μ-SCH_(2)CH=CH_(2))(μ-SPh)(A)的合成及性质见参考文献[1],配体PPh2Et系参照文献[2]的方法合成,b.p.(22mmHg)=184℃,d=1.019(26℃),PPh_(3)、甲苯为分析纯。因为配合物A遇氧分解,所有操作均在严格绝氧条件下进行。

The kinetics of nucleophilic substitution reaction of Fe_(2)(CO)6(μ-SCH_(3)CH=CH_(2))-(μ-SPh)with PPh_(3) and PPh_(2)Et has been studied.The results showed that.PPh3 could displace one carbonyl of the complex while with PPh_(3)Et as substi-tuent a two step substitution could exist in the complex.The reaction followed a two-term rale law.One term implied S_(N)2 substitution and the other implied isomerization.The rate constants for these reactions and their corresponding activation parameters have been determined,A mechanism for this reaction has been proposed.