A Novel One-Dimensional Copper Mellitate Complex Featured by {Cu(H2O)2(urea)[C6(COO)4(COOH)2]}n 2n- Polyanions
Blue monoclinic single crystals of the novel one-dimensional [H3N-(CH2)6-NH3][Cu(H2O)2(urea)(μ2-C6(COO)4 (COOH)2)]H2O coordination polymer have beenprepared in aqueous solution at room temperature in the presence of 1,6-diaminohexane andurea. Space group P21/n (no. 14) with a = 958.48(9), b = 1465.74(11), c = 1821.14(12) pm, beta= 97.655(8)°. The Cu2+ cation is coordinated in a square pyramidal manner by two oxygen atoms stemming from the dihydrogen mellitate tetraanion, one oxygen atom from the ureamolecule, and two water molecules. The Cu−O distances are between 193.3(2) and 229.4(2)pm. The connection between Cu2+ and [C6(COO)4(COOH)2]4 yields infinite chain-likepolyanions parallel to [ 01] with a composition of{Cu(H2O)2(urea)[C6(COO)4(COOH)2]}n2n-. The dihydrogen mellitate tetraanion adopts a μ2coordination mode. The [(H3N-(CH2)6-NH3)]2+ cations are accommodated between the chainsas counter cations. The hexane-1,6-diammonium cations adopt a partial synclinal conformation. The chains are connected by strong and weak hydrogen bonds. Magneticmeasurements reveal a paramagnetic Curie-Weiss behaviour and a magnetic moment of 1.93μB per Cu2+. Thermoanalytical investigations in air show that the complex is stable up to 135°C. Following decomposition processes yielding CuO.