A new coordination polymer of Zn(II)-btc (H₃btc 5 benzene- 1,3,5-tricarboxylic acid) with protonated acridine: Synthesis, crystal structure and spectroscopic properties

A new Zn(II)-btc coordination polymer 1 (H₃btc = benzene-1,3,5-tricarboxylic acid) containing protonated acridines was synthesized by hydrothermal reaction at 165 °C for 3 days and characterized by FT-IR, UV-Vis, Fluorescence, TGA measurements and single-crystal/powder X-ray crystallography. The crystallographic data for 1: monoclinic, P21/n, a = 11.0100(5), b = 16.7104(7), c = 11.7492(5) Å, β = 98.735(2), V = 2136.56(16) Å3, Z = 4, T = 130(2) K, Dc = 1.572 g cm^-3, F(000) = 1036, μ(Mo Kα) = 1.205 mm^-1, GOF= 1.005. R₁ = 0.0427, wR₂ = 0.1410 [I>2σ(I)]. Structural analysis also revealed that the btc^3- ligands bridge four-coordinate Zn(II) centres to form a 2-D grid-like layer network on the bc plane. The protonated acridines fill up the cavities formed between adjacent layers and combine the 2-D layers to generate a non-interpenetrating 3-D supramolecular framework through the hydrogen bondings and π · π packing interactions. The fluorescence investigation disclosed that 1 shows multiband emissions over a wide range.