Four inorganic-organic hybrid complexes built from tetravanadate and macrocyclic oxamide

Four inorganic-organic hybrid compounds, [M-2(CuL)(4)(V4O12)]2H2O (M=Co (1), Mn (2)), [Mn-2(NiL)(4)(V4O12)]2H2O (3), and [Zn-2(CuL)(4)(V4O12)]2CH3OH2H2O (4) (ML, H2L=2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien), have been synthesized and characterized by elemental analysis, IR, UV, fluorescence spectra, and X-ray diffraction analysis. Single-crystal X-ray analysis reveal that both [V4O12](4-) and M2V4 adapt a chair-like configuration in four structures. The cyclovanadate group [V4O12](4-) is a tetradentate bridging ligand linking two [M(ML)(2)](2+) fragments, producing centroantisymmetric heterometallic hexanuclear [M2M4] complexes. The variable-temperature magnetic susceptibility measurements (2-300K) of 1 and 2 show weak antiferromagnetic interactions.