Synthesis and Magnetic Properties of μ-Terephthalato Binuclear Cobalt(II) Complexes

Abstract Three Co(II)-Co(II) binuclear complexes have been synthesized, namely [CO2(TPHA)(L)4](ClO4)2 (L = 2,2′-bipyridyl (bpy), 1,10-phenanthroline (phen) and 4,4′-dimethy1-2,2′-bipyridyl (Me2bpy)), where TPHA is the terephthalato dianion. Based on IR, elemental analyses, conductivity measurements and electronic spectra, these complexes are proposed to have extended TPHA-bridged structures and to consist of two cobalt(II) ions in a distorted octahedron evironment. The temperature dependence of the magnetic susceptibility of [Co2(TPHA)(bpy)4](ClO4)2 H2O and [Co2(TPHA)(phen)4](ClO4)2 H2O has been studied giving the exchange integral J = -0.96 cm−1 and J = -0.93 cm−1, respectively. This indicates a weak antiferromagnetic interaction between the metal ions.