有机锡化合物结构与电极性能的构效关系研究

Study on the Relationship between Structure of Organotin Complexes and Characteristics of Liquid Membrane Electrodes

系统研究了三类有机锡化合物的阴离子响应行为.结果表明,有机锡化合物的结构与电极响应行为之间呈现出非常密切的构效关系.三类有机锡化合物对水杨酸根离子均呈现出选择性的电位响应性能,其中四配位有机锡化合物对水杨酸根离子呈现近Nernst响应,而五、六配位有机锡化合物对水杨酸根离子均呈现超Nernst响应.更重要的是,载体中心原子上正电荷密度对电极响应性能有很大影响.随着与锡原子相连的有机基团性质的变化,载体对水杨酸根离子的电位响应性能和选择性均发生规律性的变化,通过Hammett常数定性地描述了载体结构与电极性能的构效关系.同时,通过交流阻抗、膜红外光谱等技术对电极响应机制作了初步探讨,并对超Nernst现象和六配位有机锡化合物的响应行为进行了解释.

We systematically investigated the response characteristics upon anions of three types of organotin (@) complexes. The results show that there are close relationship between the potentiometric response characteristics and structure of organotin (@) complexes. These complexes exhibit selective potentiometric response to salicylate. The electrodes based on tetracoordinated organotin complexes show near - Nernst response to salicylate while the electrodes based on pentacoordinated and hexacoordinated organotin complexes show super - Nerst response to salicylate. Above all, the response characteristics are influenced heavily by properties of the central metal. As properties of organic groups that connect directly to tin atom change, the potentiometric response characteristics and selectivity vary regularly. The relationship between structure of carriers and electrode performances are described by Hammett constant. The response mechanism was also investigated by use of impedance and IR spectroscopic techniques. The super - Nernst phenomena and response characteristics of electrodes based on hexacoordinated organotin complexes were also interpreted in this paper.