The effect of coordination habits of metal ions on fabricating metal-organic frameworks with thiophenedicarboxylate

Two new Metal-Organic Frameworks, [Zn3(tdc)3(H2O)2]·2.5(dioxane) (1) and [Mn3(H2O)3(tdc)3(dioxane)]·2(dioxane) (2), have been successfully constructed by the utilization of 2,5-thiophenedicarboxylate ligand (H2L) and Zn/Mn ions. Although trinuclear metal secondary building units (SBUs) have been stabilized in these two final frameworks, the different connection modes are exhibited due to the difference of coordination habits of metal ions. The trinuclear [Zn3(COO)6] SBU exhibits the 6-connected mode via six L ligands, whilst the trinuclear [Mn3(COO)6] SBU presents the 8-connected mode via six L ligands and two p-dioxane molecules. The different connection modes of two trinuclear SBUs lead to the formation of distinct topological structures (6-connected pcu for 1; 8-connected tsi for 2). Both of the activated samples for these two MOFs could reserve the certain porosities and exhibit the corresponding gas sorption for H2.