Structural analysis of tris(5-methyl- [1,3,5]-dithiazinan-2-yl)stibine, its reactions with chalcogens. Intramolecular chalcogen-bonding interactions

• Published in: Journal of molecular structure 2020-01, Vol.1200, p.127050, Article 127050
• Main Authors: Villaseñor-Granados, Tayde Osvaldo, Montes-Tolentino, Pedro, Rodríguez-López, Germán, Sánchez-Ruiz, Sonia A., Flores-Parra, Angelina
• Format: Article
• Language: English
• Subjects: bis(5-methyl-[1,3,5]-dithiazinan-2-yl)-sulphide; bis(5-methyl-[1,3,5]-dithiazinan-2-yl)selenide; Intramolecular chalcogen-bonding interactions; tris(5-methyl-[1,3,5]-dithiazinan-2-yl)stibine
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2019.127050

We report the synthesis of three new compounds: tripodal tris(5-methyl- [1,3,5]-dithiazinan-2-yl)stibine (5), and its bipodal products: bis(5-methyl- [1,3,5]-dithiazinan-2-yl)sulphide 7 and bis(5-methyl- [1,3,5]-dithiazinan-2-yl)selenide 8. Compounds 7 and 8 were obtained by reaction of 5 with sulphur and selenium. Structures were mainly determined by X-ray diffraction and NMR analyses. Compounds were also calculated and the nature of the Sb–C, S–C and Se–C bonds was analysed. The total electrostatic potentials allowed to determine the electronic distribution in the molecules. Chalcogen bonds Sb⋅⋅⋅S, Se⋅⋅⋅S and S⋅⋅⋅S were observed. In sulphides and selenides S⋅⋅⋅S⋅⋅⋅S and S⋅⋅⋅Se⋅⋅⋅S tricentric interactions were also found. Intramolecular interactions were confirmed by visualisation of molecular orbitals, bond paths and critical points. The weakest interactions were also observed by the reduced gradient maps of the molecular electronic density. In order to determine the donor-acceptor character of each species involved in such interactions, NBO analyses were applied. •First examples of stibine, sulphide and selenide bearing heterocyclohexyl substituents.•Spontaneous transformation of (5-methyl-[1,3,5]-dithiazinan-2-yl)3Sb into (5-methyl-[1,3,5]-dithiazinan-2-yl)2S is reported.•S⋯S and Sb⋯S Interactions stabilise a crowded (5-methyl-[1,3,5]-dithiazinan-2-yl)3stibine.•Chalcogen bonds and Sb⋯S interactions studied by X-ray analysis and electronic structure calculations.•Tricentric chalcogen interactions (S⋯S⋯S and S⋯Se⋯S) in (5-methyl-[1,3,5]-dithiazinan-2-yl)2sulphide and selenide.