POLYMERIC 2-DIMENSIONAL AND 3-DIMENSIONAL TRANSITION-METAL NETWORKS -CRYSTAL-STRUCTURES AND MAGNETIC-PROPERTIES

A strategy for the design of molecule-based magnets consists of assemb ling transition-metal ions in two-dimensional (2D) or three-dimensiona l (3D) networks in order to maximize the interactions between the magn etic centers. While increasing the dimensionality of the compounds, an increase in T-C the critical temperature of spontaneous magnetization should, in principal, be favoured. We are currently studying material s that are formed by the interaction of transition-metal ions with the oxalate ligand, C2O42-, and will present a straightforward concept fo r building up achiral 2D and chiral 3D homo- and bimetallic networks. Whereas a variety of metal ions can be incorporated, a correlation of the magnetic behavior and the relationship to the special topology of e.g. the chiral, cubic 3-connected 10-gon net (10,3) is not yet fully understood.