Crystal and molecular structure, electron spin resonance, and electronic spectrum of tetrakis(imidazole)dinitratocopper(II)

The structure of the title compound has been established by single-crystal X-ray analysis. Crystals are orthorhombic, space group Pna21, a = 13.85(1), b = 9.83(1), c = 13.39(1) Å, Z = 4. The structure was solved by the heavy-atom method and atomic paramters were refined by full-matrix least-squares calculations tyo R 0.043 for 1 394 stattistically significant reflections from diffractometer measurements. The copper atom has a tetragonally distorted octahedral co-ordination in which four imidazole nitrogen atoms define the basal plane, mean Cu-N 2.011 Å, and unidentatate nitrato-oxygen atoms occupy the axial sites, mean Cu-O 2.566 Å. The mean copper atom displacement from the nitrato-group planes is 0.80 Å. The imidazole N-H groups all participate in an extensive N-H ⋯ O hydrogen bonded network involving one the nitrato-oxgen atoms. The single-crystal e.s.r. and polarised electronic spectra are also reported and the electronic structure of the chromophore discussed with reference to these and the crystallographic data.

Duke Scholars

Author Andrew T. McPhail Chemistry