Two Preparation Methods-dominated Cd^(Ⅱ)-Based Coordination Polymers with Mixed Adenine Nucleobase and 5-Nitroisophathalate Ligands: Synthesis, Structure and Fluorescence

Two new CdⅡ-based coordination polymers(CPs) with mixed adenine(Hade) nucleobase and 5-nitroisophathalate(nip) ligands, {[Cd(Hade)_(0.5)(H_2O)_2(nip)]·H_2O}n 1 and {[Cd(Hade)(H_2O)_(1.25)(CH_3OH)0.75(nip)]·0.75 CH_3OH·0.5H_2 O}_n 2, were successfully obtained by varying the preparation methods and structurally characterized. Crystal data for 1: monoclinic, C2/c space group with a = 10.5546(6), b = 17.3496(6), c = 16.1198(9) ?, β = 104.2800(10)o, V = 2860.6(2) ?3, Dc = 2.058 g/cm^3, Mr = 443.13, Z = 8, F(000) = 1752, μ = 1.585 mm^(–1), the final R = 0.0394 and wR = 0.1109 for 2285 observed reflections with I > 2σ(I). For 2: triclinic, P1 space group with a = 10.2032(7), b = 10.5098(8), c = 11.0223(8) ?, a = 65.7050(10)o, β = 74.5750(10)o, g = 61.5280(10)o, V = 943.38(12) ?~3, Dc = 1.888 g/cm3, Mr = 536.24, Z = 2, F(000) = 537, μ = 1.225 mm^(–1), the final R = 0.0225 and wR = 0.0702 for 3143 observed reflections with I > 2σ(I). 1 presents a crisscrossed layer with mutually orthogonal {Cd(nip)} chains aggregated by neutral m-N(7),N(9)-Hade connector. By contrast, 2 displays a linear chain with CdⅡ ions extended by bis-bidentate chelating-nip2–connectors, which are further assembled into a broad ribbon by N-H···N hydrogen-bonding interactions. Additionally, the two solid-state samples with comparable thermal stability exhibit favorable luminescent emissions at room temperature, suggesting their potential applications as fluorescence materials.