Topological Diversity, Adsorption and Fluorescence Properties of MOFs Based on a Tetracarboxylate Ligand

The combination of a tetradentate ligand, N,N,N',N'-benzidinetetrabenzoate (BenzTB), with paddle-wheel SBUs based on Zn, Co or Cu has led to a series of new metal-organic frameworks (MOFs) with different structural motifs, depending on the additional acid present and the reaction temperature. Isomorphous compounds M-2(H2O)(2)(BenzTB) [DUT-10(M), M = Zn, Cu, Co] crystallize in the Imma space group (sp. gr.) and adopt the lvt topology, whereas the use of Zn and Cu under modified crystallization conditions gives rise to new phases Zn-2(H2O)(2)(BenzTB) (sp. gr. Cccm, DUT-11) and Cu-2(H2O)(2)(BenzTB) (sp. gr. P4/mnc, DUT-12) with pts and ssb framework topologies, respectively. DUT-10(Zn) exhibits selective gas sorption properties for H-2 and CO2 over N-2 and solvent-induced change in fluorescence.