ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis, Crystal Structure, and Magnetic Properties of a Novel Trinuclear Mixed-Valence Oxo-Bridged Manganese Complex Formed by Ligand-Substituted Reaction Mn₃O(ClC₆H₅CO₂)₂(CH₃C₆H₅CO₂)₄(3-Methylpyridine) 0.5CH₃CN

B. Yan

Department of Chemistry, Tongji University, Shanghai 200092, P. R. China

E-mail: byan@tongji.edu.cn

Received: 22 March 2002

Abstract: A trinuclear mixed-valence oxo-centred manganese complex has been synthesized by carboxylic acid-substituted reaction in CH₃CN solution Mn₃O(ClC₆H₅CO₂)₂(CH₃C₆H₅CO₂)₄(3- Methylpyridine) · 0.5CH₃CN. It is a novel trinuclear Mn complex with mixed carboxylate bridge. The title complex crystallizes in the orthorhombic system, space group Pbca, with unit cell dimensions a = 22.548(5) Å, b = 23.070(5) Å, c = 24.321(3) Å, V = 12651(5) ų, Z = 4, R₁ = 0.0755, and wR₂ = 0.1627. The crystal structure shows an oxo-centred Mn₃O unit with peripheral ligands provided by two different bridging carboxylic acids ligands (m-chlorobenzoic acid and m-methylbenzoic acid) and terminal 3-methylpyridine group. The variable temperature magnetic susceptibility (1.8—300 K) for the title complex has been measured and interpreted in terms of the Kambe vector-coupling method and Van Vleck equation, and the values of J, J', and g are −8.42 cm⁻¹, −10.37 cm⁻¹, and 2.04 cm⁻¹, respectively. This indicates a weak antiferromagnetic exchange coupling among the manganese ions for the complex.

Full paper in Portable Document Format: 572a102.pdf

Chemical Papers 57 (2) 102–107 (2003)