The crystal structure of Hexakis(2-pyridone)copper(II) perchlorate

Abstract

Crystals of hexakis(2-pyridone)copper(II) perchlorate, [Cu(C₅H₅NO)₆] (ClO₄)₂, are monoclinic, a 9.453(2), b 10.492(3), c 17.794(4) Ǻ, β 95.57(2)°, space group P2₁/c with Z = 2. The structure was solved by Fourier methods using X-ray diffractometer data and refined by block-diagonal least-squares to convergence at R 0.037, R_w 0.044 for 3054 independent reflections. The octahedral coordination of the copper atom in the centrosymmetric cation is tetragonally distorted with Cu-O bond lengths of 1.922(2), 1.952(2) and 2.546(2) Ǻ. The ligands are in the pyridone tautomeric form and coordinate the copper atom through the exocyclic oxygen atoms. There are N-H...O bonding interactions between the ligands in the equatorial plane and the axial ligands (N...O distances of 2.781(3) and 2.894(3) Ǻ). The perchlorate ions (Cl-O, 1.412-1.436 Ǻ) are hydrogen-bonded to the N-H groups of the axial ligands (N...O 2.958 Ǻ.