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

Cu (II) complexes with violuric acid ligand were synthesized, and the relat ionship between the structures and magnetic properties of these complexes w ere 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 t wo-dimensional sheet structures for some cases (2, 3). The temperature depe ndence of the magnetic susceptibility of 1 revealed the low-dimensional ant iferromagnetic interactions. The marked g-shift for L was observed from the temperature dependence of the ESR spectra. From the Xray diffraction at 17 3 K, it is revealed that the marked g-shift for I originates in the coopera tive Jahn-Teller assisted hydrogen-bonding variation.