Chalcogen 'like-like' interactions involving trisulphide and triselenide compounds: A combined CSD and ab initio study

Abstract

In this manuscript, we combined a search in the Cambridge Structural Database (CSD) and ab initio calculations (RI-MP2/def2-TZVPD level of theory) to analyze the ability of trisulphide and triselenide moieties to establish chalcogen 'like-like' interactions. A preliminary CSD inspection revealed two predominant structural patterns, depending on the anti or syn conformation adopted by the substituents of the S3/Se3 bridge, leading to bifurcated or double chalcogen bonding interactions, respectively. In order to analyze these two relevant structural motifs we have used a series of S and Se derivatives Ch3χ2 (Ch = S and Se and X = H, F, CN, and CF3) which act as both electron donor (using the lone pairs) and acceptor (using the σ-holes) entities. Besides, we have carried out "atoms in molecules" (AIM) and natural bonding orbital (NBO) analyses to further describe and characterize the chalcogen bonding interactions described herein. As far as we know, chalcogen⋯chalcogen interactions involving trichalconides (S3/Se3) have not been previously described in literature a may be of great importance in the preparation and characterization of new solids based on this subclass of σ-hole bonding.