Two-dimensional metal-organic frameworks containing linear dicarboxylates

The solvothermal synthesis of four two-dimensional metal-organic frameworks containing linear dicarboxylic acids as ligands for Zn-II centres is described. Zn(BDC)(DMF) [( 1) where BDC = benzene-1,4-dicarboxylic acid; DMF = N,N-dimethylformamide] adopts a common paddlewheel motif leading to a 4(4) grid network, whereas Zn-3(BDC)(3)(EtOH)(2)(2), Zn-3(BDC)(3)(H2O)(2)center dot 4DMF (3) and Zn-3(BPDC)(3)(DMF)(2)center dot 4DMF ( 4) each form networks with the relatively uncommon 3(6) topology based upon Zn-3(O2CR)(6) secondary building units. All contain coordinated solvent molecules, namely DMF [(1) and (4)], ethanol (2) or H2O (3). Comparison of structures (2) and (3) illustrates a clay- like flexibility in interplanar spacing which sheds light on the ability of the Zn-3(BDC)(3) framework to undergo desolvation and uptake of small solvent and gas molecules.