Construction of Cd(II) coordination polymers used as catalysts for the photodegradation of organic dyes in polluted water

Four Cd(II) coordination polymers formulated as {[Cd-3(tpcb)(2))(eta,eta-mu-SO4) 2(H2O)(6)]SO4 center dot 16H(2)O}(n) (1), {[Cd(tpcb)(0.75)(OH)(H2O)(2)](NO3)}(n) (2), {[Cd-2(tpcb)(SO4)(2)(H2O)(6)]center dot 2MeOH center dot 3H(2)O}(n) (3), and {[Cd(tpcb)(NO3)(H2O)(2)](NO3)}(n) (4) were synthesized by reactions of CdSO4 or Cd(NO3) 2 with tetrakis(4- pyridyl) cyclobutane (tpcb) under solvothermal conditions or at ambient temperature. Compounds 1- 4 were characterized by elemental analysis, IR spectroscopy, thermal analysis, powder X- ray diffraction analysis and single crystal X- ray diffraction. Compounds 1, 2, and 4 possess three different complicated 3D frameworks with the Schl fli symbols of (4(6))(4(12)center dot 5(4)center dot 6(4)center dot 8(8)), (6(3))(4)(6(2)center dot 8(4))(3) and (8(3))(8(6)), respectively, while 3 presents a 1D chain structure. Compounds 1- 4 exhibited relatively good photocatalytic activity towards the degradation of methyl orange (MO), methyl blue (MB) and rhodamine B (RhB) in aqueous solution. These results offered a good insight into the temperature effects on the assembly of Cd(II) coordination polymers and their photocatalytic applications.