One- and two-dimensional materials containing vanadium oxide: structures and magnetic properties of Cu(dien)V(2)O6 center dot H2O and Ni(dien)V2O6 (dien = diethylenetriamine)

The structures of a one-dimensional compound Cu(dien)V2O6. H2O 1 and a two- dimensional compound Ni(dien)V2O6 2, where dien is diethylenetriamine, have been determined by X-ray diffraction. The former is composed of corner-sha ring VO4 tetrahedra chains, with Cu(dien)(2+) fragments attached to every o ther VO4 unit. The latter has a layer structure with the V4O12 tetramers co nnected by edge-shared Ni-2(mu-O)(2)(dien)(2)(4+) dimers. The layers are fu rther stacked to form one-dimensional channels along the [001] direction. M agnetic susceptibility measurements for both compounds have been performed down to 2 K. Paramagnetic behavior is observed in 1, whereas ferromagnetic interaction is found to be dominant in 2.