Three-dimensional lanthanide coordination polymers with p-phenylenediacrylates: Syntheses, structures, and properties

Three three-dimensional lanthanide coordination polymers [Ln ₂(pda) ₂(HCOO)(OH)(H ₂O)] _n (Ln = Dy, 1; Tb, 2; Ho, 3; H ₂pda = p-phenylenediacrylic acid) have been solvothermally synthesized and their structures have been determined using either X-ray powder or single-crystal diffraction data. They are isostructural and possess a 3D architecture with the pcu (α-Po) net topology based on the parallel 1D lanthanide-oxygen rod-shaped secondary building units, each of which is connected to four other rods by the pda ligands. The photoluminescent properties of 1-3 have been investigated. Complexes 1-3 all display the intense blue emission in the solid state at room temperature. Especially, compared with the free H ₂pda ligands, 1 shows the strong fluorescence enhancement due to the complexation.