Stability Constants of Some Univalent Cation Complexes of 2,3-Naphtho-15-crown-5 in Nitrobenzene Saturated with Water

• DOI: 10.1007/s10953-009-9434-z
• Publication Date: 2009-07-20T18:34:54Z
• Authors: E. Makrlík; P. Vaňura; P. Selucký
• Keywords: 01 natural sciences; 0104 chemical sciences

The extraction of micro amounts of cesium by nitrobenzene solutions of sodium, potassium and rubidium dicarbollylcobaltates (M+B−;M+=Na+,K+,Rb+) has been investigated in the presence of 2,3-naphtho-15-crown-5 (N15C5, L). The equilibrium data were explained by assuming that ML+ and ML 2 + complexes (M+=Na+,K+,Rb+, Cs+; L=N15C5) were present in the organic phase. The stability constants of the complex species ML+ and ML 2 + have been determined in nitrobenzene saturated with water. It was found that the stability of the complex cation ML+ (where M+=Na+,K+,Rb+, Cs+; L=N15C5) in water-saturated nitrobenzene solutions increases along the series Cs+<Rb+<K+<Na+, whereas that of the species ML 2 + in the same medium increases in the order Cs+<Rb+<Na+<K+.