The chemistry of cobalt acetate -: IV.: The isolation and crystal structure of the symmetric cubane, tetrakis[(μ-acetato)(μ3-oxo)(pyridine)cobalt(III)]•chloroform solvate, [Co4(μ3-O)4(μ-CH3CO2)4(C5H5N)4]•5CHCl3 and of the dicationic partial cubane, trimeric, [(μ-acetato)(acetato)tris(μ-hydroxy)(μ3-oxo)hexakispyridinetricobalt(III)]hexafluorophosphate•water solvate, [Co3(μ3-O)(μOH)3(μ-CH3CO2)(CH3CO2)(C5H5N)6][PF6]2•2H2O

The isolation from "cobalt(III) acetate" and characterisation by single crystal X-ray diffraction (refined to R = 0.087, R-w = 0.084) of the symmetric neutral cubane, [Co-4(mu(3)-O)(4)(mu-CH3CO2)(4)(C5H5N)(4)], and of the hexafluorophosphate salt (refined to R = 0.078, R, = 0.073) of the trimeric dication, the partial cubane [Co-3(mu(3)-O)(mu-OH)(3)(mu-CH3CO2)(CH3CO2)(C5H5N)(6)](2+), are reported. The cubane crystallises as its chloroform solvate, [Co-4(mu(3)-O)(4)(mu-CH3CO2)(4)(C5H5N)(4)]. 5CHCl(3), whilst the partial cubane crystallises as its water solvate, [Co-3(mu(3)-O)(mu-OH)(3)(mu-CH3CO2)(CH3CO2)(C5H5N)(6)][PF6](2) . 2H(2)O. The cubane and partial cubane dication have average Co ... Co distances of 2.818(8), 2.683(6) and 2.918(6), 2.767(5) Angstrom, respectively, and average Co-mu(3)-O distances of 1.86 and 1.91 Angstrom, respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.