A non-covalent interaction differs from a covalent bond in that it does not involve the sharing of electrons, but rather involves more dispersed variations of electromagnetic interactions between molecules or within a molecule. Non-covalent (or weak) interactions are the dominant type of interaction between supermolecules in supermolecular chemistry, and are critical in maintaining the three-dimensional structure of large molecules (such as proteins and nucleic acids), thus, the conformation of proteins is dominated by ionic interactions and hydrogen bonds.
In addition, they are also involved in many biological processes in which large molecules bind specifically but transiently to one another (see the properties section of the DNA page). These interactions also heavily influence drug design, crystallinity and design of materials (particularly for self-assembly), and, in general, the synthesis of many organic molecules. Several non covalent interactions has been described such as: halogen bonds, chalcogen bonds, cation-π, etc.
The numerous applications of the chalcogen atoms, have imposed a significant improvement in the study, both theoretical and experimental, of these atoms and their capacity to establish weak non-bonded interactions within gas phase molecules, organic and biological systems. As a result of these investigations, new compounds with novel bonding arrangements have been discovered presenting unprecedented structures.
Amongst the whole variety of weak interactions, one of the less studied corresponds to pnictogen (also called pnicogen) bonds. In spite that pnictogen interactions have been described in the literature and known for several years , they did not attract much attention until the present decade. It was in the period 2007-2011, when Scheiner et al. and Hey–Hawkins et al. drew the attention of the scientific community to those bonds. Theirnature has been rationalized by Politzer et al. based on the s–hole concept. In the last years, the number of publications and groups involved in pnictogen bonds has grown immensely, indicating the importance of these novel interactions. We have been extensively working on the description and analysis of the pnictogen interactions found in different complexes, both inter and intramolecular ones. Besides, other groups have published several articles in the field of pnictogen interactions including nitrogen, phosphorus, and arsenic atoms.
In the last years, I have been very active in the study of non-covalent interactions, particularly hydrogen, chalcogen and pnicogen bonds, both inter and intramolecular.