Modeling of stability constants of mono-complexes of La3+, Ce3+, Pr3+, and Nd3+ with carboxylic acids in water-dioxane solutions by using connectivity index 3χv

► Two models for the estimation of stability of lanthanide complexes were developed. ► Models are suitable at low and high mass fractions of dioxane in water. ► Models enable simultaneous estimation of K1 in different water-dioxane mixtures. ► Models allow simultaneous estimation of K1 of complexes of different metals.