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Structure and magnetic property of a mixed-valence nonanuclear cobalt compound with a square-pyramidal Co(II)5 core
Zhong-Quan Jia1, Xiao-Jun Sun, Li-Li Hu
1State Key Laboratory of Physical Chemistry of Solid Surfaces & Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.
Abstract:
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.
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