THE CHEMISTRY OF COBALT ACETATE - IV - THE ISOLATION AND CRYSTAL-STRUCTURE OF THE SYMMETRICAL CUBANE, 3)-OXO)(PYRIDINE)COBALT(III)]CENTER-DOT-CHLOROFORM SOLVATE, -O)(4)(MU-CH3CO2)(4)(C5H5N)(4)]CENTER-DOT-5CHCL(3) AND OF THE DICATIONIC PARTIAL CUBANE, TRIMERIC, RICOBALT(III)]HEXAFLUOROPHOSPHATE-CENTER-DOT-WATER SOLVATE, H3CO2)(CH3CO2)(C5H5N)(6)][PF6](2)CENTER-DOT-2H(2)O

The isolation from ''cobalt(III) acetate'' and characterisation by sin gle crystal X-ray diffraction (refined to R = 0.087, R-w = 0.084) of t he 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, = 0.0 73) of the trimeric dication, the partial cubane 3)-O)(mu-OH)(3)(mu-CH 3CO2)(CH3CO2)(C5H5N)(6)](2+), are reported. The cubane crystallises as its chloroform solvate, [Co-4(mu(3)-O)(4)(mu-CH3CO2)(4)(C5H5N)(4)]. 5 CHCl(3), whilst the partial cubane crystallises as its water solvate, O)(mu-OH)(3)(mu-CH3CO2)(CH3CO2)(C5H5N)(6)][PF6](2) . 2H(2)O. The cuban e and partial cubane dication have average Co ... Co distances of 2.81 8(8), 2.683(6) and 2.918(6), 2.767(5) Angstrom, respectively, and aver age Co-mu(3)-O distances of 1.86 and 1.91 Angstrom, respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.