Structural and synthesis study of eight isostructural coordination polymers formed by 5-sulfoisophthalic acid and lanthanide ions

This work presents the synthesis and structural characterization of eight isostructural 1D coordination polymers formed by the coordination of 5-sulfoisophthalic acid with various lanthanides ions: Ln = $Ce\left(III\right),\mathrm{Pr}\left(III\right),Sm\left(III\right),Gd\left(III\right),Dy\left(III\right),$ $Ho\left(III\right),Er\left(III\right)andTm\left(III\right)$. The structures were synthetized via a two-step process, wherein a solution of lanthanide ions was added to a mixture of 5-sulfoisophthalic acid and 1,3-bis(4-pyridyl)propane, the latter serving as an auxiliary ligand. This method has proven to be a simpler approach compared to those described in the literature. The compounds were characterized by X-ray single crystal diffraction, FT-IR and Raman spectroscopy, and elemental analysis. Structural analysis revealed a significant correlation between atomic number of the lanthanide ion, unit cell parameters, and space group. On the other hand, the Hirshfeld surface analysis and the two-dimensional fingerprint plot revealed that the set of the intermolecular forces remains unchanged across different lanthanide ion.