Three oxo complexes with a tetra-nuclear [Cu4 (μ2-Cl)6(μ4-O)] unit

The three title compounds, namely 4-phenyl-1H-imidazolium hexa-mu(2)-chloro-chloro-mu(4)-oxo-tris(4-phenyl-1H-imidazole-kappa N-1)tetracopper(II) monohydrate, (C9H9N2)[Cu4Cl7O(C9H8N2)(3)]center dot H2O, hexa-mu(2)-chloro-mu(4)-oxo-tetrakis(pyridine N-oxide-kappa O) tetracopper(II), [Cu4Cl6O(C5H5NO)(4)], and hexa-mu(2)-chloro-tetrakis(2-methyl-1H-imidazole-kappa N-1)-mu(4)-oxo-tetracopper(II) methanol trisolvate, [Cu4Cl6O(C4H6N2)(4)]center dot 3CH(4)O, exhibit the same Cu4OCl6 framework, where the O atom at the centre of an almost regular tetrahedron bridges four copper cations at the corners. This group is in turn surrounded by a Cl-6 octahedron, leading to a rather globular species. This special arrangement of the Cu-II cations results in a diversity of magnetic behaviours.