INTRAMOLECULAR ANTIFERROMAGNETIC COUPLING IN SUPRAMOLECULAR GRID STRUCTURES WITH CO2+ METAL CENTERS

The magnetization of novel supramolecular grid structures consisting o f four bis(bipyridyl)-pyrimidine ligands and four Co2+ ions was measur ed, We provide evidence for an antiferromagnetic coupling of the Co2spins, Investigations of microcrystals, powders, and solutions with th e mean distance of the grids varying from 20 to 160 Angstrom showed th at the coupling is solely of intramolecular origin and is not affected by long-range ordering. Thus, these grids form an almost ideal quantu m spill system of four spins. This; is further supposed by low-tempera ture field-sweep measurements.