Similar to complex 3
the molecule of 4 is generated by inversion symmetry – here located in the middle of Cu2Cl2 ring. Each copper ion is pentacoordinated with three imidazole and two bridging chloride ligand sadopting the geometry close to square-pyramid (with N1, N3, N5
donors of 2-ethylimidazoles and bridging Cl1 (short) in Cu(II) plane
and apical Cl1# (long) anion).