Structure of a catalytically active octanuclear cobalt complex [Co(II)4Co(III)4(μ4-O)4(μ-O2CPh)12(PhCOOH)4]

The structure of a catalytically active octanuclear mixed-valence cobalt complex [Co(II) 4 Co(III) 4 (μ 4 -O) 4 (μ-O 2 C Ph ) 12 ( Ph COOH) 4 ] ( Ph = phenyl, C 6 H 5 ) has been determined using an X-ray diffraction analysis. The presence of 16 ligands containing phenyl rings in each complex gives rise to strong steric stresses and leads to a disordering of terminal groups. The compound crystallizes in the monoclinic crystal system, space group of symmetry P 2 1 / n , with the unit cell parameters a = 18.076(5) Å, b = 26.371(3) Å, c = 22.791(5) Å β = 92.48(1)°, V = 10853(4) Å 3 , Z = 4, and ρ = 1.516 g/cm 3 . The final values of the discrepancy factors are R 1 = 0.0441 for 4005 symmetrically nonequivalent reflections with I ≥ 2σ( I ), wR 2 = 0.1131, and GooF = 0.943.