Assembly of two luminescent cadmium(II) 4,4'-phosphini Co-dibenzoate coordination polymers

Two new cadmium(II) coordination polymers [Cd(HL)(H2O)]·1.5H2O (1) and [Cd(HL)(4-bpmp)0.5]·2H2O (2) (H3L = 4,4'-phosphinicobis-dibenzoic acid, and 4-bpmp = N,N'-bis(4-pyridylmethyl)piperazine) have been synthesized by self-assembly of CdCl2 with 4,4'-phosphinicobis-dibenzoate, and N,N'-bis(4-pyridylmethyl)piperazine through solvothermal/hydrothermal method. Their structures were confirmed by X-ray single crystal diffraction, infrared spectrometer (IR), and powder X-ray diffraction (PXRD) and TGA techniques. Both compounds are in Pī space group and exhibited a 2D networks constructed from dinuclear [Cd2(POO)2] or paddle-wheel [Cd2(COO)2(POO)2] units, respectively. In 2, the Cd2+ is five-coordinated and shows a rare tetragonal pyramidal geometry. At room temperature, the compounds exhibit moderately intense blue and green fluorescence emission with peaks at 381 nm and 509 nm, respectively. KEY WORDS: Cadmium(II) compounds, Photoluminescence, Carboxyphosphinate ligand Bull. Chem. Soc. Ethiop. 2024, 38(1), 85-98. DOI: https://dx.doi.org/10.4314/bcse.v38i1.7