Double π-hole tetrel-chalcogen interactions can lead to stable molecular heterodimer

After geometry optimisations, three isomers belonging to four different types of geometry were obtained. The natures of the X and Y atoms not only affect the relative stability of the isomers, but also the interaction sites available on the H 2 XY molecule.

For all the systems considered in this study, a covalent structure was obtained from a non-covalent isomeric form involving a double π-hole interaction. Such a covalent structure corresponds to the global minimum for the (SO 3 )(H 2 CS), (SO 3 )(H 2 SiO) and (SO 3 )(H 2 SiS) complexes, and a local minimum for the (SO 3 )(H 2 CO) complex. The usefulness of physically-relevant topological tools for a thorough characterisation of the monomers prior to a search for the isomeric forms of a complex is once again demonstrated.