Complementary hydrogen bonds and ionic interactions give access to the engineering of organometallic crystals

A crystal synthesis strategy based on a sequence of redox/acid-base/self-assembly/crystallisation processes has been devised and successfully applied to prepare a number of mixed organic/organometallic and organometallic/organometallic crystalline materials. An adequate choice of the building blocks permits design and construction of mono-, two- and three-dimensional superanion framework structures encapsulating organometallic cations, The superanions are generated by partial deprotonation of polyprotic acids from the reaction with the organometallic hydroxides [Cr(eta(6)-C6H6)(2)][OH] and [Co(eta(5)-C5H5)(2)][OH], produced in situ by direct oxidation of the neutral complexes [Cr(eta(6)-C6H6)(2)] and [Co(eta(5)-C5H5)(2)]. The anionic super-structures are held together by a combination of neutral and interionic O-H ... O hydrogen bonds, while the interaction with the organometallic cations is based on a profusion of C-H ... O bonds reinforced via charge assistance.