The stability constants of complex anion In(tiron)^-in mixed solvents of ethanol-water with weight percentages of ethanol being 0,5,15,25,35 and 50 have been measured spectrophotometrically at 293 K,using NaClO_4 as s...The stability constants of complex anion In(tiron)^-in mixed solvents of ethanol-water with weight percentages of ethanol being 0,5,15,25,35 and 50 have been measured spectrophotometrically at 293 K,using NaClO_4 as supporting electrolyte with ionic strength ranging from 0.1 to 3.3mol·dm^(-3). The thermodynamic stability constants of In(tiron)^-in various mixed solvents have been obtained by a polynomial approximation equation based on Pitzer's theory.As a comparison,the traditional Debye-Hückel equation has also been used to treat the same data.The results show that this polynomial approximate method is obviously superior to the old one.It was discovered that there is a linear rela- tion between the thermodynamic stability constants of In(tiron)^-and the mole fraction of organic component in mixed solvents or the reciprocal of dielectric constants of mixed solvents.The medium effect and the standard free energy of transfer,ΔG_(tr)~0,for the coordination reaction:In^(3+)+tiron^(4-)= In(tiron)^-,have also been discussed.展开更多
基金the National Natural Science Foundation of China.
文摘The stability constants of complex anion In(tiron)^-in mixed solvents of ethanol-water with weight percentages of ethanol being 0,5,15,25,35 and 50 have been measured spectrophotometrically at 293 K,using NaClO_4 as supporting electrolyte with ionic strength ranging from 0.1 to 3.3mol·dm^(-3). The thermodynamic stability constants of In(tiron)^-in various mixed solvents have been obtained by a polynomial approximation equation based on Pitzer's theory.As a comparison,the traditional Debye-Hückel equation has also been used to treat the same data.The results show that this polynomial approximate method is obviously superior to the old one.It was discovered that there is a linear rela- tion between the thermodynamic stability constants of In(tiron)^-and the mole fraction of organic component in mixed solvents or the reciprocal of dielectric constants of mixed solvents.The medium effect and the standard free energy of transfer,ΔG_(tr)~0,for the coordination reaction:In^(3+)+tiron^(4-)= In(tiron)^-,have also been discussed.
