Unravelling non-classical NCIs in chemistry and biology

Since the naissance of the field of Supramolecular Chemistry, scientists have been intrigued by the existence of new noncovalent interactions beyond the ubiquitous hydrogen bond and the classical π-stacking and ion-π interactions. This process started with the inclusion of elements from the p-block as Lewis acids species, leading to a new chemistry based on the σ-hole concept and it is still ongoing with the proposal of novel NCIs that involve transition metal elements.