Synthesis, magnetic properties and structure of the [Co 4(μ 3-Cl) 2(μ 2-Cl) 4Cl 2(THF) 6] complex

Abstract

The X-ray analysis showed that the title compound is isomorphous with the iron analogue reported previously. It exists as the centrosymmetric tetramer with two different types of cobalt(II) centres corresponding to octahedral CoCl 4O 2 and trigonal bipyramidal CoCl 4O chromophores. The four cobalt atoms, bridged by two μ 3- and four μ 2-chlorine atoms, constitute a rhombus of dimensions: 3.686(3), 3.646(3) (edges) and 3.630(3), 6.37(1) Å (diagonals). The magnetic susceptibility measured over the range 4.2–293 K suggests overall ferromagnetic interactions in the tetrameric molecule. Attempts have been made to simulate the magnetism of the tetramer with the isotropic Heisenberg model. The magnetic properties of the title compound are compared to those of its iron analogue.