- 作者: 許東明; 蔡彥香
- 作者服務機構: Department of Chemistry, National Taiwan University, Taipei, Taiwan
- 中文摘要:
Cobalt (II) and copper (II) chelates of 2-picolylamine have been studied spectrophotometrically in aqueous solution. Formation of 2-picolylamine chelates was pH dependent, and the optimum pH range of the cobalt (II) chelate was at pH 8.8-9.6, and copper(II) chelate at 4.7-6.8, respectively. the mole ratio of 2-picolylamine to both of metal(II) ions was found to be 2 to 1 stoichiometry. The spectrophotometric sensitivities are 0.23γ of Co/Cm2 and 8.9γ of Cu/Cm3, at 373mμ, pH 9.0 for Co (II) chelate and 588mμ, pH 6.0 for Cu(II) chelate. The stability constants (logK) of the chelates CoL..2+ and CuL..2+ have been evaluated at a constant ionic strength of 0.10 at 20, 25, 30, 35 and 40℃. Enthalpy and entropy changes characterizing the formation of the chelates have been calculated at 25℃. The results are collected as follows:
-⊿F°ML2 -⊿H°ML2 -⊿S°ML2
M2+ logKmL2 (Kcal/mole) (Kcal/mole) (e.u./mole)
Co2+ 10.62 14.48 27.64 44.15
Cu2+ 12.80 17.50 26.72 30.90 - 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --