By the reaction of different aromatic dicarboxylic acid with zinc nitrate, three metal-carboxylate frameworks, [Zn_3(BDC)_3(EtOH)_2](1), [Zn_3(BDC)_3(py)_2]·2DMF(2), and [Zn_3(NH_2-BDC)_3(H_2O)_2]·5DMF(3) which are constructed on the same linear trinuclear Zn_3(RCOO)_6 secondary building units, have been synthesized and characterized by X-ray diffraction analyses. Structural analyses showed that there are terephthalic acids as ligand linkers to form the hxl topological layer structures for 1 and 2. The introduction of the rigid aromatic ring ...