Uranyl triazolate formation via an in situ Huisgen 1,3-dipolar cycloaddition reaction

A two dimensional UO22+ coordination polymer, (UO2)(3)(C10H5N3O4)(2)(OH)(2)(H2O)(2), has been synthesized under solvothermal conditions. The triazolate ligand, 1-(4-carboxyphenyl)-1H-1,2,3-triazole-4-carboxylic acid (CPTAZ) has been generated via a 1,3-dipolar cycloaddition of 4-azidobenzoic acid and propiolic acid. Reactions of the UO22+ cation with both the in situ generated triazolate ligand and the presynthesized ligand have been explored. The structure, fluorescent and thermal behaviour of this material are presented, as is a discussion of the utility of in situ ligand formation versus direct assembly.