Chalcogen 'like-like' Interactions Involving Trisulphide and Triselenide Compounds: A Combined CSD and Ab Initio Study

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 S-3/Se-3 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 Ch(3)X(2) (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 sigma-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 (S-3/Se-3) 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 sigma-hole bonding.