Molecular assembly of dithiaparacyclophanes mediated by non-covalent X⋯X, X⋯Y and C-H⋯X (X, Y=Br, S, N) interactions

Abstract

Regioselectivity for the 5,8,15,18-substituted isomer over the 5,8,14,17-isomer was observed in a series of mercaptan-bromide coupling reactions leading to the formation of 2,11-dithia[3.3]paracyclophanes. Their molecular assembly was established by X-ray crystallographic studies. In the crystal packing of these paracyclophanes, several types of non-covalent interactions including halogen-halogen interaction, halogen-bonding interaction, weak hydrogen-bonding interaction, etc. are observed in crystals 3a, 3b and 3c. There is evidence to indicate that weak non-covalent Br⋯Br, Br⋯S, Br⋯N, C-H⋯S, S⋯S and C-H⋯N interactions play an important role in governing their molecular assembly assumed in the solid state. The attractive interactions of Br⋯Br, Br⋯S and Br⋯N are also rationalised and supported in terms of the density functional theory calculations.