Construction of a New 2D Cadmium(II) Coordination Polymer Based on N- and O-Donor Ligands: Synthesis, Luminescence and Biological Activities

A new 2D Cd(II) coordination polymer, {[Cd(4-cpa) (bpp)(2)H2O]center dot(4-cpa)center dot(H2O)} (n) (1) [4-cpa = 4-chlorophenoxyacetate, bpp = 1,3-bis(4-pyridyl)propane] has been hydrothermally synthesized and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. Complex 1 consists of discrete 2D cadmium complex, 4-cpa counter ions and free water molecules, which are assembled into a 3D supramolecular structure through hydrogen bonds and pi center dot center dot center dot pi stacking interactions. Three-dimensional fluorescence spectra of 1 were detected at room temperature under the excitation and the emission wavelengths in the range of 300-600 nm with the interval of 5 nm. The lifetime of the excited state of 1 upon excitation of 443 nm in solid-state at room temperature is 30.21 ns. The 4-cpa ligand and complex 1 have been screened for their phytogrowth-inhibitory activities against Brassica campestris L. and Echinochloa utilis Ohwi et Yabuno, and the results are compared with the activity of sodium 2,4-dichlorophenoxyacetate.