A 2D layered Cd(II) coordination polymer supported by in situ generated tetracarboxylate ligand: luminescence sensing for Co²⁺ ions

Abstract

A new Cd(II) coordination polymer of [Cd(H 2 L)(4,4'-bipy)(H 2 O)] n (1, H 4 L = 4- [(3,4-dicarboxyphenyl)disulfanyl]benzene-1,2-dicarboxylic acid, 4,4'-bipy = 4,4'-bipyridine) was hydrothermally synthesized. The H 4 L ligand was in situ generated via the formation of disulfide bond between two 4-sulfanylbenzene-1,2-dicarboxylic acid molecular. The in situ generated H 4 L ligand deprotonated two protons into H 2 L 2À , which acts as a bidentate ligand to connected Cd(II) ions into a 2D layered structure with the assistance of 4,4'-bipy ligands. The solids of 1 emits strong blue luminescence, and can be used as a luminescence probe for the detection of Co 2 + ions. The limit of detection (LOD) of Co(II) ions by 1 was calculated to be 5.4 μM.