Unusual molecular complexes of antimony fluoride dimers with acetonitrile and pyridine: structures and bonding

The structures of two new molecular complexes of antimony pentafluoride with pyridine (Py) and acetonitrile (AN), SbF5 center dot Py and Sb2F10 center dot AN, and a molecular complex of antimony trifluoride Sb2F6 center dot Py and its ionic derivative [HPy](+)[Sb2F7](-) in the solid state have been determined by single crystal X-ray structural analysis. The complexes Sb2F10 center dot AN and Sb2F6 center dot Py are the first structurally characterized compounds of dimeric antimony fluorides. To reveal the nature of bonding in the complexes and their stability, DFT computations of the electronic structure and thermodynamic characteristics were performed, in particular the analysis of the electrostatic potentials, the orbital interactions and the topology. The results indicate that the intermolecular SbMIDLINE HORIZONTAL ELLIPSISF interactions can be described as a network of pnictogen bonds.

Automated summary

The structures of two new molecular complexes of antimony pentafluoride with pyridine and acetonitrile, as well as a molecular complex of antimony trifluoride in the solid state, were determined by single crystal X-ray structural analysis. DFT computations were performed to analyze the electronic structure and stability of the complexes, revealing a network of pnictogen bonds in the intermolecular interactions.