Synthesis and magnetic properties of one-dimensional metal oxalate networks as molecular-based magnets

摘要

The homo- and heteropolymetallic assemblies ofMM'(OX)_2(H_2O)_4, where MM' represents MnMn, CoMn,NiMn, CuMn, CoCo, NiCo, CuCo, NiNi, CuNi, and CuCu; andthe respective complexes, numbered 1-10, have been prepared byreacting metal (II) salts-i.e. of Mn, Co, Ni, AND Cu-and potassiumoxalate monohydrate in hot water (90-100 deg C). The magneticsusceptibility data of the complexes 8 and 9 in the 300K-20Ktemperature range obeys the Curie-Weiss law and exhibits Weissconstants-50K and –100K, respectively. On lowering thetemperature, the effective magnetic moment decreases graduallyand is indicative of antiferromagnetic phase transition. Thecomplexes have also been characterized by ES mass spectrometry,infrared (IR), electronic, and electron spin resonance (ESR) spectra.