In(Ⅲ)-1-苯基-3-甲基-4-噻吩甲酰基-吡唑啉酮-5配合物吸附波的研究

Study on the Adsorptive Wave of Indium-HPMTHP Complex

在pH3.0的HCl-NaAc介质中,In(Ⅲ)与1_苯基_3_甲基_4_噻吩甲酰基_吡唑啉酮_5(HPMTHP)生成配合物,于-0.63V(vs.SCE)处出现一尖锐、灵敏的极谱峰,In含量在0.002～1μg/mL范围内与峰高呈线性关系。用多种电化学方法研究了极谱波的性质及反应机理,证明-0.63V处的极谱波为配合物吸附波,峰电流由中心离子In(Ⅲ)还原产生。用直线法测得配合物组成为n[In(Ⅲ)]∶n(HPMTHP)=1∶1,表观稳定常数为2.96×103。

In(Ⅲ)reacted with1_phenyl_3_methy_4_thenoylpyrazalone_5(HPMTHP)in a medium of HCl-NaAc(pH3.0)to form a complex whose polarographic wave was sharp and sensitive at-0.63V(vs.SCE).The peak height was linear with the concentration of In(Ⅲ)in the range of0.002-1μg/mL.The properties of the polarographic wave and the mechanism of the electrode reaction were studied with diversified electrochemical methods.The results showed that the polarographic wave at-0.63V was the adsorptive wave of the complex and that the peak current produced was through the reduction of In(Ⅲ).The molar ratio of the complex was found to be1∶1,and its apparent stability constant was2.96×10 3 .