Synthesis and characterization of aryltellurium compounds including mixed-valence derivatives - evaluation of Te•••S, Te•••X and X•••X (X = Br, I) interactions

In this article we describe the synthesis and characterization of [PhTe(tu)(2)][PhTeI4] and [MesTe(tu)][PhTeX4] (tu = thiourea, X = Br, I), containing multivalent tellurium species. During the syntheses of the compounds, the formation of different species, such as [PhTe(tu)I] or [I(tu)(2)][PhTeI4] was found, which were isolated and characterized. Thiourea was used in order to explore the relevance of Te center dot center dot center dot S bonds in the solid state structures of the products compared to related compounds with Te center dot center dot center dot X and X center dot center dot center dot X bonds in their molecular structures. Different types of chalcogen-chalcogen, chalcogen-halogen and halogen-halogen interactions are described by the combination of crystallographic data and computational methods. The nature of these interactions was evaluated by the noncovalent interaction index (NCI), and quantum theory of atoms in molecules (QTAIM) analyses. (C) 2020 Elsevier B.V. All rights reserved.