A novel cobalt compound [Co(9)(HL)(4)(L)(4)Cl(2)] x (EtOH)(2)(H(2)O)(2) (H(3)L = (E)-2-2((1,3-dihydroxy-2-methylpropan-2-ylimino)methyl) phenol) has been solvothermally synthesized and structurally characterized. The compound crystallised in the space group C2/c with a = 32.624(2) A, b = 9.4814(4) A, c = 33.395(2) A, beta = 109.339(5) degrees and V = 9746.8(9) A(3). The crystal structure is a mixed-valence nonanuclear Co(II/III) oligomer, which contains a square-pyramidal Co(II)(5) core formed through mu(4)-Cl and mu(3)-alkoxo bridges and the pentanuclear Co(II)(5) core is surrounded by four peripheral Co(III) ions at the square-pyramidal base plane through mu(2)-alkoxo bridges. Magnetic properties of the compound can be considered as the magnetism of the Co(II)(5) core, and the superexchange interactions between Co(II) ions within the core were calculated with three Co(II)-Co(II) superexchange parameters by using MAGPACK software package to give J(1) = + 11.1 cm(-1), J(2) = -6.50 cm(-1), J(3) = -3.25 cm(-1), D = + 6.0 cm(-1) and g = 2.30.

Solvothermal reaction of Co(OAc)2.4H2O with H4L (H4L = 2-((2-hydroxybenzylidene)amino)-2-hydroxymethylpropane-1,3-diol) in MeCN gave a mixed-valence pentanuclear cobalt complex [Co5(HL)2(H2L)2(OAc)2].2.5H2O. Crystal structural analysis revealed that two Co(III) ions were linked to a central triangular Co(II) core through HL(3-) and H2L(2-) hydroxyl groups. Magnetic measurements showed interesting magnetic properties that were assigned to spin-orbital coupling and ferromagnetic exchange interactions.