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

Triclinic single crystals of Cu 4 (H 3 N–(CH 2 ) 9 –NH 3 )(OH) 2 [C 6 H 2 (COO) 4 ] 2 · 5H 2 O 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 Cu 2+ 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 Cu 2+ coordination polyhedra and the [C 6 H 2 (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 [H 3 N–(CH 2 ) 9 –NH 3 ] 2+ cations and water molecules, which are not connected to Cu 2+ . 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.