Theoretical study on all-metal aromatic complexes: all-metal aromatic hydrogen bond

The recent advance of the aromaticity concept into the all-metal species enlightens us to explore whether there exist all-metal aromatic hydrogen bond. In order to find out the pure π-H hydrogen bond, works have been performed to eliminate the possible effects induced by the two negative charges of Al42- and Al ⋯ H metallic hydrogen bond. Interesting enough, the delocalized π electron cloud of all-metal aromatic complexes could shield the interaction between aluminium atom and HF and only all-metal aromatic hydrogen bond is observed in the vertical orientation. Our results reveal a new kind of hydrogen bond.