Syntheses, structures and photocatalysis properties of two Cu(II)-based coordination polymers based on flexible tricarboxylate ligand

Abstract

The photocatalytic performances of the two complexes were explored by the photodegradation of methylene blue (MB) dye under UV light. The chromatography-mass spectrometry (LC-MS) was selected to discuss the catalytic process, revealing the potential photodegradation mechanism of MB. Recycling experiments also indicated that the photocatalyst is reusable and stable. Two new Cu(II)-based coordination polymers (CPs), including [Cu(HL)(H2O)(2,2′-bipy)] (1) and [Cu(HL)(bbi)] (2) (H3L =5-(4ˊ-carboxylphenoxy)isophthalic acid, bbi=1,1′-(1,4-butanediyl)bis(imidazole) and 2,2′-bipy = 2,2′-bipyridine), have been successfully synthesized and characterized. 1 shows a 1D ladder-like chain that was further expanded into a 3D supramolecular network through packing interactions and H-bonded interactions. 2 also features an infinite chain containing [Cu(bbi)2Cu] loops. The photocatalytic performances of these polymers were explored by the photodegradation of methylene blue (MB) dye under UV light. 2 has excellent degradation ability of MB (50 mL and 10 mg L − 1) could be fully photodegraded within 100 min and follows with the pseudo-first-order rate constant. In addition, chromatography-mass spectrometry (LC-MS) was selected to discuss and analyze the catalytic process, suggesting the potential photodegradation mechanism of MB. Recycling experiments also indicated that the photocatalyst is reusable and stable.