By means of acid-base potentiometric titration and the advanced BEST computer program developed by Martell et al., the deprotonation constants of four inhibitors[Aminotrimethylenephosphoinic acid(ATMP), 2-phosphino-tu...By means of acid-base potentiometric titration and the advanced BEST computer program developed by Martell et al., the deprotonation constants of four inhibitors[Aminotrimethylenephosphoinic acid(ATMP), 2-phosphino-tutane-1,2,4-tricarboxylic acid(PBTCA), polyacrylic acid(PAA, M_w=2000), poly(maleic, acrylic) acid(PMAAA, M_w=3000)], and the stability constants of the complexes of these inhibitors with Ca 2+ have been determined. And the distribution curves of ATMP at different pH values in aqueous solutions have also been given out. The result of this study can be applied to explaining the inhibition mechanism.展开更多
In this paper the Bi? ligand(pyridine 2 carboxylic acid) system was studied by direct current sampled polarography (DC _ TAST) at a fixed ratio of total ligand to total metal concentration and changing pH. The polarog...In this paper the Bi? ligand(pyridine 2 carboxylic acid) system was studied by direct current sampled polarography (DC _ TAST) at a fixed ratio of total ligand to total metal concentration and changing pH. The polarographic experimental complex formation curve (ECFC) and the theoretical complex formation curve (TCFC) were used for modelling the metal ligand system and optimizing stability constants. The ECFC, in which experimental parameters of polarography are included (a shift in a half wave potential and a variation in a diffusion controlled limiting current), appears to be a characteristic function for a particular metal ligand system. The TCFC is a theoretical curve calculated for the designed metal ligand model from mass balance equation. Five bismuth complexes MHL, ML, ML2, ML3 and ML3(OH) with their stability constants as logβ 7.54± 0.10, 7.50± 0.02, 13.91± 0.04, 18.15± 0.03 and 26.75± 0.02, respectively, are reported.展开更多
本文用示差脉冲极谱技术研究Pb(Ⅱ) 络合剂(β N 三丙酸)体系。依据实验得到的极谱峰电位的移动随溶液pH值的变化关系曲线,建立合适的金属络合物体系模型。用计算机分析程序,通过求解体系的质量平衡方程及拟合实验络合物形成曲线,优化...本文用示差脉冲极谱技术研究Pb(Ⅱ) 络合剂(β N 三丙酸)体系。依据实验得到的极谱峰电位的移动随溶液pH值的变化关系曲线,建立合适的金属络合物体系模型。用计算机分析程序,通过求解体系的质量平衡方程及拟合实验络合物形成曲线,优化得到金属络合物的稳定常数。计算机分析结果表明,在所研究的pH值范围内,溶液中存在四种金属络合物:PbH2L+、PbHL、PbL-、PbL(OH)2-,其稳定常数(logβ)分别为:16.23±0.04、12.42±0.01、4.11±0.05、9.43±0.02。展开更多
文摘By means of acid-base potentiometric titration and the advanced BEST computer program developed by Martell et al., the deprotonation constants of four inhibitors[Aminotrimethylenephosphoinic acid(ATMP), 2-phosphino-tutane-1,2,4-tricarboxylic acid(PBTCA), polyacrylic acid(PAA, M_w=2000), poly(maleic, acrylic) acid(PMAAA, M_w=3000)], and the stability constants of the complexes of these inhibitors with Ca 2+ have been determined. And the distribution curves of ATMP at different pH values in aqueous solutions have also been given out. The result of this study can be applied to explaining the inhibition mechanism.
文摘In this paper the Bi? ligand(pyridine 2 carboxylic acid) system was studied by direct current sampled polarography (DC _ TAST) at a fixed ratio of total ligand to total metal concentration and changing pH. The polarographic experimental complex formation curve (ECFC) and the theoretical complex formation curve (TCFC) were used for modelling the metal ligand system and optimizing stability constants. The ECFC, in which experimental parameters of polarography are included (a shift in a half wave potential and a variation in a diffusion controlled limiting current), appears to be a characteristic function for a particular metal ligand system. The TCFC is a theoretical curve calculated for the designed metal ligand model from mass balance equation. Five bismuth complexes MHL, ML, ML2, ML3 and ML3(OH) with their stability constants as logβ 7.54± 0.10, 7.50± 0.02, 13.91± 0.04, 18.15± 0.03 and 26.75± 0.02, respectively, are reported.
文摘本文用示差脉冲极谱技术研究Pb(Ⅱ) 络合剂(β N 三丙酸)体系。依据实验得到的极谱峰电位的移动随溶液pH值的变化关系曲线,建立合适的金属络合物体系模型。用计算机分析程序,通过求解体系的质量平衡方程及拟合实验络合物形成曲线,优化得到金属络合物的稳定常数。计算机分析结果表明,在所研究的pH值范围内,溶液中存在四种金属络合物:PbH2L+、PbHL、PbL-、PbL(OH)2-,其稳定常数(logβ)分别为:16.23±0.04、12.42±0.01、4.11±0.05、9.43±0.02。
