Influence of the solvent in the electronic spectra of azabipyridine macrocycles of zinc(II) and nickel(II)

The influence of the media on structural characteristics of bis-azabipyridi l macrocyclic ligands and their Zn and Ni complexes is analyzed by means of quantum chemical calculations applied to the interpretation of UV-visible spectra. Metallic and metal-free species are considered as case studies, fo cusing on the influence of both coordinating and non-coordinating effects o f the solvents on the structural and electronic characteristics of the syst ems. Whereas cationic structures are necessary to model a protic environment, is olated molecules are not capable of rendering a good description in a non-p olar environment, where intermolecular interactions are to be considered.