Ionic solvation—Part 7. Cation solvation and cryptate stability in mixed solvents. Studies of complex formation between silver(I) and cryptand 222 in dimethylsulphoxide + acetonitrile mixtures

✍ Scribed by Andrzej Lewandowski

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 486 KB
• Volume: 36
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(91)85329-6

✦ Synopsis

The stability constants of silver(I) complexes with cryptand 222 have been determined by potentiometric titration in dimethylsulphoxide (DMSO) + acetonitrile (AN) mixtures. It has been shown that the experimental data can be correlated via the following equation:

where KAB and KA are the cryptate stability constants in the mixture A + B (A = DMSO, B = AN) and in pure solvent A, respectively; xi is the mole fraction of the component j of the mixed solvent, n is the metal cation solvation number; fij represents the correlation parameter, which may be assigned to the overall formation constant for a complex of Ag+(DMSO), with AN molecules: Ag+(DMSO), + iAN $ Ag+(DMSO),_,(AN), + iDMS0.

Using the literature value of n = 4 for silver(I) cation solvation number, the following values of /Ii parameters were obtained from curve-fitting calculations: