碘离子选择电极中载体的配位方式对电极响应机理的影响  

Influence of Charged Additives on the Response Mechanism in Iodide-selective Electrodes

作　　者：胡昌建 彭朝英 李志强[2] 

机构地区：[1]湖南省经济贸易学校,长沙410002 [2]湖南师范大学化学系,长沙410081

出　　处：《化学传感器》1999年第1期50-56,共7页Chemical Sensors

摘　　要：本文系统研究了两类新的希夫碱Co(Ⅱ)配合物作载体的碘离子选择电极的响应行为。交流阻抗和紫外可见光谱实验证明载体对碘离子呈现出优良的电位响应性能和选择性的根本原因在于载体与碘离子之间存在独特的相互作用;荷电离子添加实验表明,载体的配位方式对碘离子选择电极的作用机制有决定性的作用。四配位Co(Ⅱ)希夫碱配合物作载体的电极通过中性载体作用机制对碘离子呈现能斯特电位响应;而六配位Co(Ⅱ)希夫碱配合物作载体的电极通过荷电离子作用机制响应碘离子。Two kinds of Co(Ⅱ) complexes of a Schiff base were used as anion ionophores for PVC membrane electrodes, these novel electrodes exhibit excellent potentiometric response and selectivity towards iodide. The results from a. c. impedance and ultra-visible spectra show that the potentiometric response and selectivity towards iodide are due to the unique interactions between the carriers and iodide ions. The response mechanism of the electrodes is considerably influenced by the charged additives. Electrodes based on tetracoordinate Co(Ⅱ) complexes of the Schiff base exhibit linear response towards iodide via a neutral carrier mechanism, but electrodes based on hexacoordinate Co(Ⅱ) complexes of the Schiff base exhibit linear response towards iodide via a charged carrier mechanism.

关 键 词：碘 离子选择电极 电极作用 载体 配位方式 

分 类 号：O657.15[理学—分析化学]