Structural studies in metal–purpurate complexes. Part 9. Crystal structure of bis(purpurato)copper(II)‘octahydrate’

Abstract

The crystal structure of a new hydrate phase of bis(purpurato)copper(II), CuL₂·≈7.6H₂O (L = purpurate, C₈H₄N₅O₆^–), has been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to a residual of 0.052 for 2 124 ‘observed’ reflections. Crystals are triclinic, space group P, with a= 12.187(4), b= 11.889(5), c= 10.447(3)Å, α= 73.57(3), β= 83.72(3), γ= 75.09(2)°, and Z= 2. Each of the purpurate ligands is symmetrically co-ordinated to the copper atom in a tridentate manner, but in consequence of Jahn–Teller distortion, considerable differences are found between them; for one ligand Cu–N is 1.973(6) and Cu–O 2.023(7), 2.029(7)Å, while for the other, Cu–N is 2.021(5) and Cu–O 2.289(5), 2.303(5)Å.