Two Zn(II)-based metal-organic frameworks, namely, [Zn-3(Hbptc)(2)(DMF)(2)]center dot 2DMF(1) and [Zn-5(bptc)(3)center dot H2O)]((CH3)(2)NH2)(2)(2), (H(4)bptc = 3,3',5,5'-biphenyltetracarboxylic acid, DMF = N,N'-dimethylformamide), have been synthesized using different amounts of nitric acid under mixed-solvothermal conditions. 1 and 2 display different coordination geometries and donor ligands for the Zn2+ ions. In 1, only three carboxylic acid groups of H(4)bptc take part in the construction of the three-dimensional (3-D) framework with Zn2+, and one remains uncoordinated that can bind to other metal ions. Postsynthetic exchange of 1 with Ln(3+) cations demonstrates that 1 can effectively capture metal cations and sensitize the visible-emitting Ln(3+).