AN ALTERNATIVE ROUTE TO OBTAIN METAL-ORGANIC FRAMEWORKS VIA SOLVOTHERMAL SYNTHESIS USING Eu₂O₃ AND 2,6-NAPHTHALENODICARBOXYLIC ACID

An alternative route to synthesis of metal-organic frameworks containing Eu(III) ion was proposed via solvothermal process in aqueous medium. The compounds of the minimal formulae [Ln₂(NDC)₃(H₂O)₄] were synthesized starting from the mixture of the 2,6-naphthalenedicarboxylic acid with europium(III) oxide. So far, this type of metalorganic framework based on the lanthanide ion synthetic route has not been investigated before as the main metal sources are nitrate and chloride salts. The structural characterizations were performed by FTIR spectroscopy, thermal analysis TG-DSC, and X-ray diffraction. The results of IR and TG were consistent with the structural determination results and complemented by X-ray diffraction patterns. SEM images also corroborate the morphologies found in recent research on this material. The materials obtained shown high-intensity luminescence, for the Eu-NDC compound, which corroborates with an energy transfer efficient of the ligand to Eu(III) ion.

Keywords:
luminescence properties; europium(III)-organic frameworks; synthetic route