Supramolecular aggregation of Ni(salen) with (C6F5)2Hg and [o-C6F4Hg]3.

As part of our ongoing interest in the supramolecular chemistry of fluorinated organomercurials, we have investigated the interaction of bis(pentafluorophenyl)mercury ((C6F5)2Hg), and trimeric (perfluoro-o-phenylene)mercury ([o-C6F4Hg]3), with nickel(II) N,N'-bis(salicylidene)ethylenediamine) (Ni(salen)). While solution studies monitored by UV-VIS spectroscopy suggest that Ni(salen) interacts with the trinuclear mercury complex in solution, the 1 : 1 adduct (Ni(salen)-(C6F5)2Hg) and the 1 : 1 adducts Ni(salen)-[o-C6F4Hg]3 and [Ni(salen)-[o-C6F4Hg]3-THF-H2O] can be obtained by slow evaporation of solutions containing the two building blocks. While arene-fluoroarene and hydrogen bonding interactions, as well as interactions between mercury and the salen ligand are the predominant forces responsible for the formation of these adducts, Ni(salen)-[o-C6F4Hg]3 and [Ni(salen)-[o-C6F4Hg]3-THF-H2O] also display short Ni-Hg separations consistent with the presence of metallophilic interactions. Quantum theory of atoms in molecules (QTAIM) analyses of the Ni-Hg interactions in these adducts finds that these interactions are dominated by electrostatic and dispersion forces, despite featuring non-negligible covalent contributions.