A Cadmium Coordination Polymer Based on Phosphate Clusters: Synthesis, Crystal Structure, Electrochemical Investigation and Antibacterial Activity

A new d 10 coordination polymer, C 5 H 14 N 2 2 Cd P 6 O 18 H 2 O 2 · 6 H 2 O n , was prepared and characterized by X-ray diffraction, IR-Raman spectroscopy, thermal analysis and cyclic voltammetry. The crystal structure determination reveals that the phosphate anions alternate with the cadmium octahedral to form an anionic coordination polymer extending along [001] direction. The double protonated homopiperazine cations and the water molecules ensure the interconnection between polymers and thus giving rise to three dimensional supramolecular networks. By means of cyclic voltammetry, it is shown that whilst the reduction of the complexed Cd 2+ occurs with a biggest difficulty than this of its free form, the anodic oxidation of the heterocyclic N donor piperazine became quite easy, when it is displayed as a counterpart diprotonated cation, between the anionic layers of Cd ( P 6 O 18 ) ( H 2 O ) 2 ) n 4 n - . The antibacterial activity of the coordination polymer is also discussed.