The rates of dissociation of thioether ligands which are imbedded in organotin(IV) compounds, such as trichloro[o-(ethylthiomethyl)phenyl]stannane, were determined by the dynamic NMR method. The dynamic processes of the corresponding ether ligands was too fast to detect as the change in line shapes in 1H NMR spectra. All the boron compounds examined, which possessed similar structures to the stannane and were of the boronate type, failed to show dissociation of a thioether or ether ligand due to their large rates of dissociation. The rates of dissociation of a thioether–tribromoboron complex were determined by the same technique. The feature of the activation parameters was that the compounds examined exhibited fairly large positive entropy of activation in accordance with other results that involve dissociation of ionic species into covalent species.
嵌入在
有机锡(IV)化合物中的
硫醚
配体的解离速率,例如三
氯[o-(乙基
硫甲基)苯基]
锡,是通过动态核磁共振(NMR)方法确定的。相应醚
配体的动态过程过快,无法通过氢核磁共振谱中的线形变化检测到。所有被检验的
硼化合物,其结构类似于
锡化合物且属于
硼酸盐类型,由于其解离速率较大,未能显示出
硫醚或醚
配体的解离。
硫醚-三
溴硼配合物的解离速率也是通过相同的技术确定的。激活参数的特点是,被检验的化合物表现出相当大的正活化熵,这与其他涉及离子物种解离为共价物种的结果一致。