Redox properties of the systems Eu(222)3+/Eu(222)2+ and (222)H22+/H2, (222)H+ in various solvents. Use as a potential reference
Résumé
The Eu(222)3+/Eu(222)2+ (222 = cryptate 222) electrochem. system is reversible and rapid in H2O, MeOH, DMSO, DMF, MeCN and tetramethylurea and can be used as a potential ref. The (222)H22+/H2, (222)H+ system allows the measurement of the difference in basicity between those solvents. The assumption that γatEu(222)3+ = γtEu(222)2+ and γt(222)H22+ = γt(222)H+ (γ = activity coeff.) leads to results similar to those based upon the γtAsPh4+ = γtBPh4- extra thermodn. hypothesis.