Sonochemical synthesis of a new nano-sized cerium(III) supramolecular compound; Precursor for nanoceria

• Supramolecular compound of (NAMH+)2[Ce4(pydc)6(pydcH)2(H2O)8]·8H2O (1) was synthesized.
• Using a sonochemical method, nanostructures of CeIII supramolecular compound 1 were prepared.
• Nanoceria was obtained from nanostructures of (NAMH+)2[Ce4(pydc)6(pydcH)2(H2O)8]·8H2O.
• Crystal structure of CeIII supramolecular compound 1 was determined by X-ray crystallography.
• The fluorescent properties of CeIII supramolecular compound 1 were studied.

Using a sonochemical method, nanoparticles of a new Ce(III) supramolecular compound, (NAMH+)2[Ce4(pydc)6(pydcH)2(H2O)8]·8H2O (1), (H2pydc = 2,6-pyridinedicarboxylic acid, NAM = nicotinamide), have been synthesized. Compound 1 was characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses, and its structure was determined by X-ray crystallography. It has been revealed that its structure consists of tetra-nuclear building units that extend to a 3D supramolecular network via non-covalent interactions mainly hydrogen bonding. The thermal stability of complex 1 both for its crystals and nanostructures has been studied by the thermal gravimetric (TG) method and compared with each other. The role of ultrasound irradiation power and the concentration of initial reactants on the size and morphology of the nano-structured complex 1, has been investigated. Ceria nanoparticles were obtained upon the calcination of complex 1 at 800 °C under atmospheric air. Furthermore, the fluorescent properties of complex 1 at room temperature were studied.