10.1007/s11173-008-1006-z

Abstract

Experimental curves of spectrophotometric titration for systems containing mononuclear homoleptic complexes were interpreted in an alternative way involving calculation of the intrinsic constants of binding of the ligand by a central ion with fixed coordination sites. This matrix approach allows one to reduce the number of variables in least-squares optimization of titration curves, describing the formation of complexes [MX n ] (n = 1–4) via three independent variables ( $$ \bar K $$ , ω cis and ω trans ) for a square planar geometry and via two variables ( $$ \bar K $$ and ω) for a tetrahedral geometry. Differences in the mutual cis-and trans-influences of coordinated ligands were quantitatively estimated for labile complexes in solution. The method proposed was used to calculate the intrinsic constants of complexation between Cu2+ and the chloride ion in methanol from spectrophotometric titration data.