Two metal–organic frameworks (MOF), [(CuCN)2.(6-mquin)2], 1 and [Me3SnCu(CN)2.(quina)2(H2O)2], 2, where (6-mquin) = 6-methyl quinoline and (quina) = quinaldic acid, have been synthesized and structurally characterized. MOFs 1 and 2 have been characterized by IR, UV-visible, and NMR spectra, as well as TGA. The emission spectra and the thermodynamic parameters from TGA of MOFs 1 and 2 were discussed. MOFs 1 and 2 were used as heterogeneous catalysts for the oxidative discoloration of Rhodamine B dye (RhB) by H2O2. The cytotoxic effect of MOFs 1 and 2 on the viability of MCF-7 cells was also determined by MTT assay. MOFs 1 and 2 have potentially good inhibition activity to MCF-7 cells.