New insights on transition metal coordination compounds with biological active azole and nitroimidazole derivatives

[Display omitted] •Geometries, coordination modes and biological activity of transition metal compounds with azole and nitroimidazole derivatives.•Non-covalent interactions play a key role on the antiparasitic and anticancer mechanism of action of the coordination compounds.•Bulky azole coordination compounds interact with the DNA major groove.•Copper nitroimidazole compounds showed electrostatic interactions with DNA minor groove, redox and ROS generation.•The nitro group is still involved in the mechanism of action the coordination compounds.•Weak interactions should be taken into consideration for the rational design of new biological active compounds. In this review we have selected some notable examples of azoles and nitroimidazoles and their coordination compounds with previously reported biological effectiveness. In an effort to further extend the discussion of these complexes and to highlight some structure-activity relationship that might have been overlooked throughout the years, a depth analysis of their crystal structures and their weak interactions was carried on. There were analysed examples of compounds with a wide range of transition metal ions, with different coordination modes and geometries. State of art of the intra and intermolecular non-covalent interactions in these compounds, such as lone pair···π, π···π, σ-hole, C-H···π, Cl∙∙∙Cl and hydrogen bonding are discussed and to have a deeper insight on the nature of relevant interactions, theoretical calculations were performed. The understanding of the coordination environment and these weak interactions may contribute to the rational design of new compounds with potential applications in bioinorganic and medicinal inorganic chemistry.