Study on the relationship between structure of organotin complexes and characteristics of liquid membrane electrodes

We systematically investigated the response characteristics upon anions of three types of organotin (IV) complexes. The results show that there are cl ose relationship between the potentiometric response characteristics and st ructure of organotin(Iv) complexes. These complexes exhibit selective poten tiometric response to salicylate. The electrodes based on tetracoordinated organotin complexes show near - Nernst response to salicylate while the ele ctrodes based on pentacoordinated and hexacoordinated organotin complexes s how super - Nerst response to salicylate. Above all, the response character istics are influenced heavily by properties of the central metal. As proper ties of organic groups that connect directly to tin atom change, the potent iometric response characteristics and selectivity vary regularly. The relat ionship between structure of carriers and electrode performances are descri bed by Hammett constant. The response mechanism was also investigated by us e of impedance and IR spectroscopic techniques. The super - Nernst phenomen a and response characteristics of electrodes. based on hexacoordinated orga notin complexes were also interpreted in this paper.