Crystal Structure of a Copper(II) Complex with 2,3-Dioxo-5,6:13,14-dibenzo-9-methyl-7,12-bis(ethoxycarbonyl)-1,4,8,11- tetraazacyclotetradeca-7,11-diene

The molecular and crystal structure of a macrocyclic N,N′-substituted-oxamidocopper(II) complex, [CuL], where H₂L = 2,3-dioxo-5,6:13,14-dibenzo-9-methyl-7,12-bis(ethoxycarbonyl)-1,4,8,11- tetraazacyclotetradeca-7,11-diene, has been determined by X-ray diffraction method. Crystal data: C₂₅H₂₄CuN₄O₆, M_r = 540.02, monoclinic, space group C2/c, a = 25.605(4), b = 9.230(2), c = 22.105(4) Å, β = 111.749(4)°, V = 4852(2) ų, Z = 8, D_c = 1.478 g/cm³,μ (Mo-Kα) = 0.949 mm^-1, F(000) = 2232, R = 0.0681 and wR = 0.1666 for 2747 observed reflections with I ≥ 2σ(I). The copper atom is located in the coordination cavity formed by the four nitrogen donors of the deprotonated macrocyclic oxamido ligand with a distorted square-planar geometry. In the crystal, two molecules are connected by the Cu⋯O weak coordination bonds to produce a supramolecular quasi-dimer.