イオンと溶媒の相互作用に関する研究(VI) : アセチルアセトン中のカドミウムイオン : 他溶媒間錯生成反応とその溶媒間移行ギブス自由エネルギー

The complex formation constants (βn) of the cadmium ion in acetylacetone (2, 4-pentanedione, Hacac) with other solvents S and its Gibbs free energies of transfer (ΔG^0_<tr>) have been detennined polarographically. The values of ΔG^0_<tr>(Cd^<2+> : Hacac→S) (in kJ mol^<-1>) and βn, where n is the maximum coordination number detected, are as follows; -9.7 and log β_4 = 2.53 for acetone, -45.5 and log β_6 = 4.63 for water, -24.3 and log β_5 = 3.20 for EtOH, -85.3 and log β_5 = 7.63 for N, N-dimethylformamide, -83.7 and log β_6 = 8.22 for N, N-dimethylacetamide, and -110.0 and log β_8 = 12.7 for dimethyl sulfoxide. The correlation between the ΔG^0_<tr> and βn values is discussed on the basis of the coordination model of ionic solvation. The results for the cadmium ion are shortly discussed in comparison with those for the silver and sodium ions.