Synthesis, X-ray crystal structure and X-band EPR of [Cu(H2O)2(imH)4]·Sq single crystals

The copper salt [Cu(H2O)2(imH)4]·Sq has been synthesized at room temperature. Crystal structure of the [Cu(H2O)2(imH)4]·Sq (Sq is squarete dianion (C4O42−) and imH is imidazole (C3H4N2)) complexes has been investigated by single-crystal X-ray diffraction analyses and the environment of copper ion has been identified by EPR. The single crystal is triclinic with the space group P1. The unit cell dimensions of the crystals are a = 9.317 Å, b = 9.958 Å, c = 12.130 Å, α = 69.99°, β = 76.61° and γ = 78.13°. The unit cell contains two molecules. The Cu(II) atom has an octahedral arrangement in which the Cu(II) ion lies on the inversion canter and is coordinated by four imidazole ligands with the equatorial plane and two water molecules with the octahedral axial. The complex shows a normal magnetic moment and the single crystal EPR spectra consist of two sets of four hyperfine lines of copper. The ground wave function of the hole of the Cu2+ is an admixture of dx2−y2dx2−y2 and dz2dz2 states.