Enhancing Metal-Organic Framework Net Robustness by Successive Linker Coordination Increase: From a Hydrogen-Bonded Two-Dimensional Supramolecular Net to a Covalent One Keeping the Topology

This work is to emphasize the influence of the synthetic procedures in the isolation of different coordination polymers (CPs) that coexist under hydrothermal conditions, and to determine, both experimental and theoretically, the driving forces that govern the reaction in the Yb-III/3,5-DSB/Phen system, to give the following Yb-metalorganic frameworks (MOFs): [Yb(3,5-DSB)(Phen)(2)(H2O)(2)]center dot(H2O)(1/2) (RPF-20-initial) in which all the reactant are stoichiometrically incorporated into the compound; the one-dimensional [Yb(3,5-DSB)(Phen)(H2O)(2)]center dot H2O,(RPF-20-prec), in whose structure hydrogen bonds built up a SP 2-periodic (6,3) Ia supramolecular net; the covalent two-dimensional (2D) [Yb(3,5-DSB)(Phen)(H2O)]center dot H2O, (RPF-20-Yb), with exactly the same (6,3) Ia net topology as its precursor; and the [Yb(3,5-DSB)(Phen)(2)(OH)(3)(H2O)], (RPF-24-Yb) built up from tetranuclear Yb4O14N8 secondary building units. Computational studies have determined the relative energies for the formation of four successively obtained compounds. From the crystallographic (structural and topological) study it is also shown, that it is possible to go from a hydrogen bonded 2D supramolecular net to the covalent one, keeping the topology.