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Determination of Stability Constants of Copper(II)‐Glycine Complex in Mixed Solvents by Copper(II)‐Selective Electrode
Author(s) -
Fan Jing,
Shen Xuejing,
Wang Jianji
Publication year - 2001
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/1521-4109(200109)13:13<1115::aid-elan1115>3.0.co;2-9
Subject(s) - chemistry , copper , dimethylformamide , inorganic chemistry , aqueous solution , solvent , methanol , stability constants of complexes , ionic strength , organic chemistry
The first stability constants (in logβ 1 form) of the Cu(II)‐glycine complex have been determined at 25 °C and ionic strength of 0.10 mol/L in water and in mixed aqueous solutions of methanol (MeOH), ethanol (EtOH), dimethylsulfoxide (DMSO), N,N‐dimethylformamide (DMF) and 1,4‐dioxane (DOX) from pH and pCu measurements of cells containing a copper(II) ion‐selective electrode. In general, the stability constants of the complex increase with increasing composition of the co‐solvents in the order: DOX>DMF>DMSO>EtOH>MeOH>H 2 O. An approximate linear relationship between logβ 1 and the mole fraction of the co‐solvent was observed for the complex in all the mixed solvents except in DMF+H 2 O mixtures. The response of the ion selective electrode to copper(II) ion in the mixed solvents was also investigated. The effects of solvent on the complex stability are discussed in terms of the polarity of the solvents.