Antimony vs. bismuth: structural differences in Cat{[MCl5](I2)} halogen bond-linked supramolecular complexes

Abstract

Four new hybrid chloroantimonates(III) and chlorobismuthates(III) with halogen bond-linked I₂, (H₂bpe){[MCl₅](I₂)} (M = Sb(III) (1); M = Bi(III) (2); bpe = 1,2-bis(4-pyridil)ethane) and (H₂bpp){[MCl₅](I₂)} (M = Sb(III) (3); M = Bi(III) (4); bpp = 1,3-bis(4-pyridil)propane), were synthesized via a reaction between Sb₂O₃/Bi₂O₃, I₂ and the corresponding bis(pyridines) in HCl. Despite sharing the same formulae of supramolecular anionic parts, they showed significant structural diversity, revealing three different structural types. Features of the halogen bond in 1–4 were examined via theoretical methods.