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

Abstract

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