Two lanthanide-bound 1H-benzotriazole polymers: New potential metal–organic scaffold for solid-phase organic chemistry

Two new two-dimensional (2D) lanthanide-organic frameworks based on H2btca and oxalate mixed ligands, namely, {Ln(Hbtca)(C2O4)(H2O)2]·(H2O)}n (Ln = Sm 1, Ho 2; H2btca = benzotriazole-5-carboxylic acid), were obtained by the solvothermal reaction of H2btca, ammonium oxalate and corresponding lanthanide nitrate. Compounds 1–2 are isostructural and both exhibit 2D layers with uncoordinated 1H-benzotriazole moieties, which are further self-assembled to form a three-dimensional (3D) supramolecular structure through hydrogen bonds. TGA and variable-temperature PXRD studies indicate desolvated 1 has excellent thermal stability, which is a new potential metal–organic scaffold for solid-phase organic chemistry. Furthermore, the luminescence properties of 1–2 are investigated at room temperature in the solid state.