Polynuclear MnII Complexes with Chloroacetate Bridge − Syntheses, Structure, and Magnetic Properties

Three new polynuclear MnII complexes with chloroacetate bridges were obtained and characterized by X-ray diffraction: [Mn3(μ-ClCH2COO)6(bpy)2] (1), [Mn2(μ-ClCH2COO)2(phen)4](ClO4)2 (2), and [Mn(μ-ClCH2COO)2(phen)]n (3). The Mn···Mn distance for 1 (3.624 Å) is smaller than for 2 (4.613 Å) and 3 (4.530 Å); this is in agreement with the number of carboxylate bridges. The three compounds show a weak antiferromagnetic coupling. The J values are −3.82 cm−1 for 1, −0.85 cm−1 for 3, and no coupling was observed for 2. Each compound showed a characteristic EPR spectrum at 4 K. Simulation of these spectra could be obtained with D = −0.16 cm−1 and E = −0.015 cm−1 for compound 1, and D = −0.045 cm−1 and E = −0.004 cm−1 for compound 2. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)