(Dipy) has been studied by electronic absorption spectroscopy. Mathematical modeling has demonstrated that
the most probable mathematical models to describe the experimental dependences of absorption on the medium
acidity and concentration of solution components relies on the dissociation constants of the ligands (Ki) and
stability constants (
) of homoligand, heteroligand, and polynuclear complexes of general composition [NimDipynEdtar]2m–4r (m = 1–4, n = 0–8, r = 0–1) as parameters. The reaction equilibrium constants and sta-
bility constants of the resulting complexes have been calculated. The structures of these complexes have been
suggested.