Low-dimensional molecule-based magnets with hydrogen-bonded network

Cu (II) complexes with violuric acid ligand were synthesized, and the relationship between the structures and magnetic properties of these complexes were examined, focussing on the role of the hydrogen-bonded network on their magnetic properties. The X-ray crystal structural analyses show that these complexes form three-dimensional hydrogen-bonded network (1), as well as two-dimensional sheet structures for some cases (2, 3). The temperature dependence of the magnetic susceptibility of 1 revealed the low-dimensional antiferromagnetic interactions. The marked g-shift for L was observed from the temperature dependence of the ESR spectra. From the Xray diffraction at 173 K, it is revealed that the marked g-shift for I originates in the cooperative Jahn-Teller assisted hydrogen-bonding variation.