New Coordination Polymers of Selected Lanthanides with 1,2-Phenylenediacetate Linker: Structures, Thermal and Luminescence Properties

Abstract

Solvothermal reactions of lanthanide (III) salts with 1,2-phenylenediacetic acid in N,N′-dimethylformamide (DMF) solvent lead to the formation of the metal complexes of the general formula Ln2(1,2-pda)3(DMF)2, where Ln(III) = Pr(1), Sm(2), Eu(3), Tb(4), Dy(5), and Er(6), 1,2-pda = [C6H4(CH2COO)2]2−. The compounds were characterized by elemental analysis, powder and single-crystal X-ray diffraction methods, thermal analysis methods (TG-DSC and TG-FTIR), infrared and luminescence spectroscopy. They exhibit structural similarity in the two groups (Pr, Sm, and Eu; Tb, Dy, and Er), which was reflected in their thermal behaviours and spectroscopic properties. Single-crystal X-ray diffraction studies reveal that Sm(2) and Eu(3) complexes form 2D coordination polymers with four crystallographically independent metal centers. Every second lanthanide ion is additionally coordinated by two DMF molecules. The 1,2-phenylenediacetate linker shows different denticity being: penta- and hexadentate while carboxylate groups exhibit bidentate-bridging, bidentate-chelating, and three-dentate bridging-chelating modes. The infrared spectra reflect divergence between these two groups of complexes. The complexes of lighter lanthanides contain in the structure coordinated DMF molecules, while in the structures of heavier complexes, DMF molecules appear in the inner and outer coordination sphere. Both carboxylate groups are deprotonated and engaged in the coordination of metal centers but in different ways in such groups of complexes. In the groups, the thermal decomposition of the isostructural complexes occurs similarly. Pyrolysis of complexes takes place with the formation of such gaseous products as DMF, carbon oxides, ortho-xylene, ethers, water, carboxylic acids, and esters. The complexes of Eu and Tb exhibit characteristic luminescence in the VIS region, while the erbium complex emits NIR wavelength.

A Top-Down Approach and Thermal Characterization of Luminescent Hybrid BPA.DA-MMA@Ln2L3 Materials Based on Lanthanide(III) 1H-Pyrazole-3,5-Dicarboxylates

“…Methane molecules as the product of BPA molecules' degradation showed significant diagnostic bands in the range 3200-2950 cm −1 with a characteristic maximum at 3015 cm −1 due to the stretching vibrations of CH bonds. Evidence of 4-propylphenol formation as the bisphenol A decomposition product is reflected in the presence of the band at 2937 cm −1 from the stretching vibrations of CH 2 groups within the propyl substituent [51][52][53][54]. The reference spectrum of the compound fits well the experimental one.…”

Crystal-to-crystal investigations of highly thermally stable three-dimensional coordination polymer based on sodium(I) ions and 4,4’-stilbenedicarboxylic acid

“…To continue our research on coordination polymers based on aromatic polycarboxylate ligands (Głuchowska et al, 2022;Głuchowska et al, 2021;Łyszczek et al, 2021;Łyszczek et al, 2019;Łyszczek et al, 2022), we present the synthesis, structure, and characterization of the first sodium threedimensional coordination polymer based on the 4,4'-stilbenedicarboxylic acid (H2SDC). This complex was obtained from an aqueous solution utilizing EasyMax102 synthesis workstation.…”

Recent Developments in Multifunctional Coordination Polymers

“…Their utility as excellent catalysts has been demonstrated in CO 2 cycloaddition reactions with epichlorohydrin under ambient CO 2 pressure and solvent-free conditions. Moreover, the effective application of a diverse range of coordination polymers and metalorganic frameworks in many cutting-edge domains of materials science is only continuing to expand [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80].…”