Theoretical Investigation of Cyano-Chalcogen Dimers and Their Importance in Molecular Recognition.

In this manuscript the different noncovalent interactions established between (HYCN)2 dimers (Y=S, Se and Te) have been studied at the MP2 and CCSD(T) level of theory. Several homodimers have been taken into account, highlighting the capacity of these compounds to act both as electron donor and acceptor. The main properties studied were geometries, binding energy (Eb ), and molecular electrostatic potential (MEP). Given the wide application of chalcogen bonds, and more specifically of cyano-chalcogen moieties in molecular recognition, natural bond orbital (NBO), "atoms-in-molecules" (AIM), and electron density shift (EDS) analysis were also used to analyse the different noncovalent interactions upon complexation. The presence of hydrogen, chalcogen and dipole-dipole interactions was confirmed and their implications on molecular recognition were analysed.