Magnetic Properties of Oxygen Centered Trinuclear Ruthenium(III) and Rhodium(III) Complexes

The magnetic susceptibility and ESR of triangular trinuclear coordination compounds, [Ru3(μ3-O)(μ-CH3COO)6(py)3]+ and [Ru3(μ3-O)(μ-CH3COO)6(py)3]+ salts of powders, were measured in the region between liquid-He temperature and room temperature. Ru(III) ions are in the low spin state and Rh(III) ions are diamagnetic. The experimental results were analyzed using a localized model with antiferromagnetic exchange interactions, while taking the molecular orbital moment Zeeman effect into consideration. A weak magnetic interaction through the μ-CH3COO bridges is discussed. The averaged g-factor of the Ru salt was about 2.26, and the best-fit antiferromagnetic exchange interaction was about J = −69.5 cm−1.