A family of uranyl-aromatic dicarboxylate (pht-, ipa-, tpa-) framework hybrid materials: photoluminescence, surface photovoltage and dye adsorption

Abstract

Four uranyl complexes [(UO₂)(pht)H₂O]·H₂O (pht = phthalic acid) (1), (UO₂)₂(Hipa)₄(H₂O)₂ (Hipa = isophthalic acid) (2), (UO₂)(tpa)(DMF)₂ (tpa = terephthalic acid) (3) and (UO₂)(box)₂ (box = benzoic acid) (4) were synthesized by the reaction of UO₂(CH₃COO)₂·2H₂O as the metal source and phthalic acid, isophthalic acid, terephthalic acid or benzoic acid as the ligand. They were characterized by elemental analyses, IR, UV-Vis, XRD, single crystal X-ray diffraction analysis and thermal gravimetric analysis. The structural analysis reveals that complex 1 exhibits a one-dimensional chain structure constructed by the building unit [(UO₂)₂(pht)₄(H₂O)₂] and further extends the chain into a 2D supramolecular architecture by hydrogen bonding interactions. Complex 2 is a discrete [(UO₂)₂(Hipa)₄(H₂O)₂] structure, and by the hydrogen bonding interaction, forms a 3D supramolecular structure. In complexes 3 and 4, adjacent uranyl polyhedra form a 1D chain through bridging terephthalic acid and benzoic acid, respectively. In order to extend their functional properties, their photoluminescence, surface photovoltage and dye adsorption properties have been studied.