- 作者: 林瑞摓; 江月娥; 秦憲新
- 作者服務機構: Department of Chemistry, National Taiwan University
- 中文摘要: Experiments were carried out at 25℃ and μ od 0.1M. Spectrophotometric and potentiometric methods gave the ionization constants of ferron, pK1=2.50±0.02 and pK2=7.12±0.02 Cu(II) and ferron form a sparingly soluble 1:1 complex, [Cu(H2O)2L]0 (L: ferronate ion) which in higher acidity media, protonates to give [Cu(H2O)2HL]+ and in lower acidity media, ionizes to give [Cu(H2O)(OH)L]¯. At pH 2.3, the 1:1 complex gives a minimum solubility and the intrinsic solubility was found to be 1.1×10¯4. the Job's continuous variation method and the molar ratio method gave a formation constant (—pK) for Cu2+ +L2⇌CuL, 10.8±0.1 in the pH range of 0.64 to 1.18 and in the pH range of 5.0 to 5.5 (optimum pH condition for formation of complex), the stoichiometry of the Cu(II)-ferron chelate is essentially 1:2 (Cu:L) but with slight tendency to form 1:1 chelate if [L]/[Cu] is less than 2. the overall formation constant (—pK) was determined to be 20.0±0.3.
- 英文摘要: --
- 中文關鍵字: --
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