Potentiometric determination of equilibrium constants for Ag(I)-pyridine,Ag(I)-2,2′-bipyridine and Ag(I)-1,10-phenanthroline systems in acetonitrile

The composition and the complex formation constants of Ag(I) with pyridine, 2,2′-bipyridine, and 1,10-phenanthroline were determined by the potentiometric method. The measurement procedure can be reduced to the determination of the EMF of the concentration cell: $$\begin{gathered} Ag|c_1 AgNO_3 (AN) + 0.1 M(C_2 H_5 )_4 NClO_4 (AN)||0.1 M(C_2 H_5 )_4 NClO_4 (AN) || \hfill \\ c_2 AgNO_3 (AN) + x L(AN) + 0.1 M (C_2 H_5 )_4 NClO_4 (AN)|Ag. \hfill \\ \end{gathered}$$ All complexes have coordination number 2. The solubility product for Ag(1,10-phenanthroline)₂NO₃ in acetonitrile was also determined. In all measurements the association of AgNO₃ was considered. Differences in the stability of analogous complexes in water and acetonitrile are discussed.