Slow relaxation of the magnetization in Oximato-bridged heterobimetallic Copper(II)-Manganese(III) chains

The use of the oximato-containing copper(II) complexes, [Cu(Hdeg)2] (H2deg = diethylglyoxime), [Cu(Hmeg)2] (H2meg = methylethylglyoxime) and [Cu(Hdmg)2] (H2dmg = dimethylglyoxime), as ligands toward manganese(II) acetate in methanol afforded the heterobimetallic compounds of formula [MnCu(deg)2(CH3COO)(H2O)2] (1), [MnCu(meg)2(CH3COO)(H2O)2] (2) and [MnCu(dmg)2(CH3COO)(H2O)2] (3) where the starting manganese(II) ion was oxidized to manganese(III) by air. In the lack of single crystals suitable for X-ray diffraction analysis, X-ray absorption techniques (EXAFS and XANES) at 40 K were used for the structural characterization of 1-3. The analysis of the X-ray absorption data reveals that 1-3 ar…