Synthesis, crystal structure, and magnetic properties of tetranuclear complexes containing exchange-coupled dilanthanide-dicopper(lanthanide = gadolinium, dysprosium) species

By reacting CuSatnOH (CuSatnOH = [N-(3-aminopropyl)salicylaldiminatoh]y droxocopper(I1)) with rare-earth hexafluoroacetylacetonates (hfac), complexes of general formula Ln(hfac)$uSatnOH (Ln = Gd, Dy) were obtained. The crystal structure of the dysprosium derivative was determined through X-ray diffraction at room temperature: the complex crystallizes in the triclinic system, space group P i , with a = 12.386 (5) '4, b = 13.574 (3) '4, c = 13.918 (4) '4, a = 69.38 (2)", p = 65.35 (6)O, y = 69.93 (S)", and Z = 2. The gadolinium derivative was found to be isomorphous. The magnetic properties of both compounds and their EPR spectra are reported. The magnetic properties of the gadolinium derivative are discussed together with previous data reported in the literature, and a spin-polarization model is suggested to justify the observed ferromagnetic coupling between gadolinium and copper. The relevance of these data to the magnetic properties of high-T, superconductors is also discussed.