First-principles study of square chalcogen bond interactions and its adsorption behavior on silver surface

Research on 2ChMIDLINE HORIZONTAL ELLIPSIS2N (Ch = S, Se, Te) square chalcogen interaction has attracted extensive attention in recent years. By search of the Crystal Structure Database (CSD), square chalcogen structures with 2ChMIDLINE HORIZONTAL ELLIPSIS2N interactions were widely found. Herein, dimers of 2,1,3-benzothiadiazole (C6N2H4S), 2,1,3-benzoselenadiazole (C6N2H4Se) and 2,1,3-benzotelluradiazole (C6N2H4Te) from CSD were chosen to construct a square chalcogen bond model. The square chalcogen bond and their adsorption behavior on Ag(110) surfaces have been systematically studied using first principles. Furthermore, partially fluoro-substituted C(6)N(2)H(3)FCh (Ch = S, Se, Te) complexes were also considered for comparison. The results show that in the C(6)N(2)H(4)Ch (Ch = S, Se, Te) dimer, the strength of the 2ChMIDLINE HORIZONTAL ELLIPSIS2N square chalcogen bond is in the order of S < Se < Te. In addition, the strength of the 2ChMIDLINE HORIZONTAL ELLIPSIS2N square chalcogen bond is also enhanced by F atom replacement in partially fluoro-substituted C(6)N(2)H(3)FCh (Ch = S, Se, Te) complexes. The self-assembly behavior of dimer complexes on silver surfaces is guided by van der Waals interactions. This work provides theoretical guidance for the application of 2ChMIDLINE HORIZONTAL ELLIPSIS2N square chalcogen bonds in supramolecular construction and materials science.