Synthesis and Magnetic Properties of P-Terephthalato Binuclear Chromium(III) Complexes

Four new terepthhalato-bridged binuclear chromium (III) complexes have been synthesized and characterizaed. Based on the elemental analyses, molar conductance and magnetic moments of room temperature measurements, and spectroscopic studies, extended TPHA-bridged structures consisting of two chromium (III) ions, each in an octahedral enviroment are proposed for these complexes. The [Cr2(TTPHA)(Me2bpy)4](NO3)4 (1) and [Cr2(TPHA)(Me2phen)4](N)3)4 (2) complexes were characterized by variable temperature magnetic susceptibility (4-300 K) measurements and observed data were successfully simulated by the equation based on the spin Hamiltonian operator H=-2JS1*S2, giving the exchange integrals J=-2,98 cm-1 for (1) and J=-3,15 cm-1 for (2). This result indicates the presence of a weak antiferromagnetic spin-exchange interaction between the metal ions within each molecule.