Crystal structure and fluorescence/phosphorescence of two novel Cd(II) coordination polymers

Two novel Cd(II) coordination polymers [Cd₄(C₆H₄O₂N)₈(H₂O)₄]_n (1) and [Cd₂(C₁₀H₂O₈)(H₂O)₆]_n (2) have been synthesized under hydrothermal condition and structurally characterized. Crystal data: (1), orthorhombic, Pbca, a=11.4494(19) Å, b=12.0969(6) Å, c=17.4073(8) Å, V=2410.9(4) ų, Z=8, D _calc=2.064 g·cm⁻³; (2), triclinic, P , a=5.5962(7) Å, b=7.7758(6) Å, c=9.6975(10) Å, α=111.981(5)°, β=101.649(6)°, γ=98.240(5)°, V=371.95(7) ų, Z=2, D _calc=2.603 g·cm⁻³. Complex (1) possesses three-dimensional infinite structure, while complex (2) adopts two-dimensional layers and the layers are connected by the many types of hydrogen bonds, forming three-dimensional network. Study results of the photophysical properties show that both complexes can emit strong blue fluorescence and complex (1) also emits phosphorescence (λ ^pl _max=511 nm, τ=32 ms) in the solid state at room temperature.