Spectrophotometric Study of the Binary System Ni(II)-N-[2-Thyenilmethyliden]- Aminopropane and the Determination of Ni(II)

摘要

The spectrophotometric study of Ni(II) - N-[2-thyenilmethyliden]-aminopropane (Schiff base derived from 2-thiophencarbaldehyde with aminopropane) was achieved and a spectrophotometric method of determining Ni(II) with this reagent is suggested.From the study of the dependence of the absorbance on the pH it results that a single complex combination is formed for the pH=6.98,corresponding to the molar ratio Ni(II)/N-[2-thyenilmethyliden]-aminopropane=1/2.The complex thus formed has pK =10.2391 ± 0.0755 for 95% probability at 25 °C temperature and ionic strength n = 0.4,indicating a satisfactory stability of the complex.The formed complex is a cation.The Lambert-Beer law is verified in the concentration range 0.11742- 4.93164 mu g Ni(II)/mL (lambda=600nm) making possible the spectrophotometric determination of Ni(II) with N-[2-thyenilmethyliden]-aminopropane (L) in this range of concentration.The molar absorptivity is calculated to be 1.075 centre dot 10~4 Lmol~(-1) cm~(-1) proving a good sensitivity of the proposed method.The method has been applied for the determination of Ni(II) in various synthetic and real samples.The method proposed for Ni(II) determination is sensitive,selective,simple,reproducible,accurate and is not affected by systematic errors.