Solvothermal reactions of Zn(NO3)2·6H2O or Cd(NO3)2·4H2O with 1,3-bis(4-imidazolylphenoxy)propane (popmz) and benzophenone-4,4-dicarboxylic acid (H2bpda) afforded two coordination polymers [Zn(bpda)(popmz)]n (1) and {[Cd(bpda)(popmz)]·0.5H2O}n (2), respectively. Both compounds were characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 has a 3D supramolecular structure consisting of two-fold parallel interwoven layers featuring hydrogen-bonding and π···π interactions. Compound 2 possess an extended 3D supramolecular architecture based on 2D layers through hydrogen-bonding interactions and the π···π stacking interactions. A comparative study on their photocatalytic activity toward the degradation of methyl orange in polluted water was explored. Reactions of Zn(NO3)2 or Cd(NO3)2 with 1,3-bis(4-imidazolylphenoxy)propane (popmz) and benzophenone-4,4-dicarboxylic acid (H2bpda) afforded two novel coordination polymers with different topologies. The Cd(II) coordination polymer exhibited good catalytic activity of methyl orange (MO) photodegradation. [ABSTRACT FROM AUTHOR]