Well‐Defined Stibonic and Tellurinic Acids

Upon going from the 4th to the 5th period a qualitative change in the molecular structures of pnictogenic and chalcogenic acids takes place. Unlike the lighter monomeric Group 15 and 16 congeners, the depicted stibonic and tellurinic acids adopt μ2-oxo-bridged dinuclear structures featuring Sb and Te atoms with trigonal-bipyramidal coordination. DFT calculations on the model compounds give dissociation energies of the dimers.