One-dimensional cadmium(II) coordination polymers: Structural diversity, luminescence and photocatalytic properties

Abstract

Three cadmium(II) complexes formulated as [Cd3L(CH3COO)4]·H2O (1), [Cd2L(NO3)2]·CHCl3 (2) and [Cd5L2(CH3COO)6] (3) have been obtained by reacting appropriate CdII salts with N,N’-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine (H2L). X-ray single-crystal analysis shows that compounds 1-3 crystallize in the triclinic space group P1¯ and consist of CdII ions with distorted octahedral geometry, connected to form trinuclear (1) and binuclear (2) units and a combination of both in 3. A piperazine moiety, in chair conformation, acts as a bridge between these polynuclear units to form 1D chains. Blue luminescence in the range of 460−490 nm was observed upon excitation at 345 nm in the solid state. The investigation of the degradation of the dye Congo Red (CR) under visible light, revealed very good photocatalytic activity of the obtained coordination polymers. The photocatalytic process follows first-order reaction kinetics.