Modification of the supramolecular structure of [(thione)IY] (Y = Cl, Br) systems by cooperation of strong halogen bonds and hydrogen bonds

Abstract

Four interhalogen complexes of heterocyclic thione ligands N-methylbenzothiazole-2-thione (mbtt) and 2(3)H-benzothiazole-thione (btt) with strong and tunable S⋯I halogen bonds were synthesized and characterized by X-ray single crystal diffraction. The study of the strength and nature of the interactions was supported by computational analysis using the Quantum Theory of Atoms in Molecules (QTAIM). Halogen bond and hydrogen bond directed self-assemblies of thione compounds were efficiently modified by the changes in the halogen bond donor and acceptor structures. In structures [(mbtt)ICl] (1) and [(mbtt)IBr] (2) the interplay of halogen bonds and hydrogen bonds between the thione hydrogens and negatively charged halogens afforded three-dimensional network structures. The strong hydrogen bonds between the polarized interhalogen and azole hydrogen in the compounds [(btt)ICl] (3) and [(btt)IBr] (4) hindered the formation of weaker interactions. Instead of network structures the 3 and 4 afforded 2D tape structures directed by strong S⋯I halogen bonds and X⋯H(NH) hydrogen bonds.