Structural and thermal studies of some [Ln 2 (Gly) 6 ·nH 2 O](ClO 4 ) 6 complexes

Lanthanides complexes are crucial for modern technologies, paving the way for advancing biomedicine, data storage, and environmental remediation. In the present study, the crystal structures of the perchlorate complexes [Ln2(Gly)6·nH2O](ClO4)6 (where Ln = Sm, Eu, Gd, Dy, and n = 9, 9, 9, 7 for samarium, europium, gadolinium, and dysprosium complexes, respectively) were determined by single-crystal X-Ray diffraction at temperature of −173 °C. A similar triclinic crystal system was observed for all complexes, and their cell parameters were determined. A new bridging mode between two metal centers was noted. In the Sm, Gd, and Eu structures, all tridentate bridging ligands were in the trans position relative to each other, while in the Dy structure, they were located in the cis position. These structural data were consistent with the thermal analysis, which showed that the removal temperatures of coordinated water differed. Specifically, the Dy complex exhibited the lowest removal temperature at 173 °C, followed by Sm and Eu at 184 °C, whereas the Gd complex displayed the highest thermal stability for coordinated water at 196 °C. Evaluating the structure and thermal stability of lanthanide complexes aids in the synthesis of materials with desirable performance characteristics.