Diorganotellurium(IV) Dihalides and Secondary Bonding: Revisiting the Coordination Polyhedra

The coordination geometry of the central atom in diorganotellurium(IV) halides, almost invariably described as ψ- trigonal bipyramidal, is in fact much more diversified. If intra and intermolecular secondary bonds and electron lone pairs are considered ψ-trigonal bipyramidal, ψ-octahedral, ψ-pentagonal bipyramidal and some others coordination geometries can be identified. A careful reexamination of a number of published structures is presented, with the analysis of the coordination polyhedra.