【摘要】 <正> 有关锑(III)-次氨基三乙酸配合物的极谱研究、其稳定常数及形成机理迄今未见报道.本文用动力可逆波半波电位移动法,测定了锑(III)-次氨基三乙酸配合物的稳定常数及反应自由能等热力学函数. 实验 883型笔录式极谱仪,以Ag-AgCl,4M NaCl为参比电极,浴温255±0.2℃.滴汞电极于440mHg时,在0.1M氯化钾溶液中的汞流量为3.9mg/g,自由滴下时间为2.5s.通氮除氧并加入0.01％聚乙烯醇作为极大抑制剂.自装控时敲击器.pHS-2型酸度计.79-1型伏安分析仪.更多还原

【Abstract】 The polarographic behaviours of Sb （III） complex with nitrilotriacetic acid （NTA）, including the calculation of its stability constant and thermodynamic function as well as the mechanism of complex formation, have been studied. On the addition of a certain amount of NTA to an acidic solution of Sb （III） containing 4M sodium chloride, two waves corresponding to three electrons electrode reaction of Sb （III） appear. It is observed that an increase in pH of the supporting electrolyte or in concentration of NTA results in an increase of the second wave （at more negative potential）. The limiting current of the total wave remains constant and is independent of the concentration of NTA and pH values. The first wave is reversible and kinetically controlled by rate of chemical reaction, whereas the sum of both wave is diffusion controlled. This is proved by the dependence of the wave height on the height of the mercury reservoir, by the time beater, by the temperature dependence and by the hanging mercury drop electrode. It is concluded that the second wave corresponds to the reduction of SbX complex while the first one to the reduction of Sb （III） ion which is controlled by the dissociation rate of SbX complex. Stability constant of SbX complex is found to be 4.6×10¹¹ by using the equation for the shift of half-wave potential of kinetic wave at given condition （concentration of sodium chloride and NTA, etc.）.更多还原