Synthesis, Crystal Structure, Hydrogen Bonding, and Thermal Behavior of a Three‐Dimensional CuII‐benzene‐1,2,4,5‐tetracarboxylate Templated by 1,9‐Diaminononane

Abstract

AbstractTriclinic single crystals of Cu4(H3N–(CH2)9–NH3)(OH)2[C6H2(COO)4]2·5H2O were prepared in aqueous solution at 80 °C in the presence of 1,9‐diaminononane. Space group P$\bar{1}$ (no. 2) with a = 1057.5(2), b = 1166.0(2), c = 1576.7(2) pm, α = 106.080(10)°, β = 90.73(2)° and γ = 94.050(10)°. The four crystallographic independent Cu2+ ions are surrounded by five oxygen atoms each with Cu–O distances between 191.4(3) and 231.7(4) pm. The connection between the Cu2+ coordination polyhedra and the [C6H2(COO)4]4– anions yields three‐dimensional framework with negative excess charge and wide centrosymmetric channel‐like voids. These voids extend parallel to [001] with the diagonal of the nearly rectangular cross‐section of approximately 900 pm. The channels of the framework accommodate [H3N–(CH2)9–NH3]2+ cations and water molecules, which are not connected to Cu2+. The nonane‐1,9‐diammonium cations adopt a partial gauche conformation. Thermoanalytical measurements in air show a loss of water of crystallization starting at 90 °C and finishing at approx. 170 °C. The dehydrated compound is stable up to 260 °C followed by an exothermic decomposition yielding copper oxide.