Synthesis, crystal structure, and properties of CuL(N3)H2O

The compound CuL(N-3)(H2O) where L = 1, 15-diaza-3,4:8,9-dibenzo-5,8-trioxacyclopentadecane-N-acetatic acid has been synthesized and characterized. X-ray crystallography reveals that copper(II) is five-coordinated in a square-pyramidal environment. The complex is a monoclinic system, a= 8.523(3)Angstrom, b=9.844(4)Angstrom c=25.895(9)Angstrom, beta =97.69(3)degrees, V = 2153.4(3) Angstrom (3), Z = 4, lambda (MoKalpha) = 0.71073, R-W = 0.0757 for 3081 observed reflections [I> 2 sigma (I)]. The copper atom is surrounded by two nitrogen atoms of the macrocycle, one oxygen atom from the carboxyl group in the ligand, one nitrogen atom from the azide group and one oxygen atom of coordinated water in a distorted square-pyramidal arrangement. The stability constant (5.8 x 10(6)) of the complex, whose compostion is in the 1:1 metal:ligand molar ratio, was measured by electronic spectra in dimethyl formamide (DMF) as solvent. The EPR spectrum of the complex shows g(perpendicular to) = 2.0373 and g(\ \) = 2.250. The results comfirm that the structure of the complex is a distorted square pyramid.