Hydrogen Bonds of C=S, C=Se and C=Te with C-H in Small-Organic Molecule Compounds Derived from the Cambridge Structural Database (CSD)

Abstract

Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discussed before. It has been mentioned in previous studies that the proton of the H-C group could be involved in hydrogen bonding, but with conventional acceptors. In this study, we explored the ability of hydrogen bond formation of Se, S and Te acceptors with the H-C donor using Cambridge Structural Database in conjunction with Ab Initio calculations. In the CSD, there are respectively 256, 6249 and 11 R 1 ,R 2 ,-C=Se, R 1 ,R 2 ,-C=S and R 1 ,R 2 ,-C=Te structures that form hydrogen bonds, in which the N,N groups are majority. Except for C=S acceptor which can form a hydrogen bond with its C, C group, both C=Se and C=Te acceptors could form a hydrogen bond only with N,C and N,N groups. CSD analysis shows very similar d (norm) around −0.04 Å, while DFT-calculated interaction for N,C and N,N groups are also similar. Both interaction distances derived from CSD analysis and DFT-calculated interaction energies demonstrate that the acceptors form stable complexes with H-CF 3 . Besides hydrogen bonds,