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The influence of medium on the stability of coordination compounds 4. The system In(tiron) − ‐NaC1O 4 ‐C 2 H 5 OHH 2 O
Author(s) -
Guo YuHong,
Liang ChunYu,
Liu QiTao
Publication year - 1992
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.19920100204
Subject(s) - tiron , chemistry , electrolyte , thermodynamics , activity coefficient , ionic bonding , polynomial , inorganic chemistry , ion , organic chemistry , aqueous solution , physics , electrode , enzyme , superoxide , mathematical analysis , mathematics
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 relation 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 , for the coordination reaction: In 3+ + tiron 4‐ = In(tiron) − have also been discussed.