Synthesis and characterized three Zn(II)-based mixed geometry coordination polymers and photocatalytic activity against dyes

Abstract

Three novel Zn(II)-based CPs (coordination polymers) with formula [Zn3(μ3-OH)(L)(H2O)5]n (1), [Zn5(L)2(bpz)2(H2O)2]n (2) and [Zn2(HL)(bip)(H2O)2·H2O]n (3) (H5L = 3,5-di(2ʹ,4ʹ -dicarboxyphenyl)benozoicacid, bpz = 3,3ʹ,5,5ʹ-tetramethyl-4,4ʹ-bipyrazole and bip = 3,5-bis(1-imidazoly)pyridine have been synthesized hydrothermally by O and N donor ligands. The single x-ray diffraction reveals that CPs are mixed geometry. In CP 1, Zn1 is square pyramidal geometry and Zn3 is distorted octahedral. In CP 2, Zn1 is tetrahedral; Zn2 is distorted octahedral and Zn3 is square pyramid geometry. In CP 3, Zn metals are distorted octahedral. By interacting with intra- and intermolecular hydrogen bonds, all CPs are stable. The nature of these CPs is semiconducting. Methyl blue (MB), Methyl orange (MO), Methyl violet (MV), and Rhodamine B (RhB) are examples of organic pollutants against which the photocatalytic activity of CPs is studied. CP 3 (25 mg) have higher photocatalytic activity against MV (20 ppm) under pH 6 condition.