A novel hydroxo-bridged cyclic tetranuclear copper(II) complex using the guanazole ligand: Synthesis, crystal structure and thermal analysis

A novel hydroxo-bridged cyclic tetranuclear copper(II) complex with the guanazole ligand (3,5-diamino-1,2,4-triazole = Hdatrz), [Cu-4(datrz)4(mu(2)-OH)(2)(NO3) (H2O)(6)] center dot (NO3) center dot 5(H2O) (1) has been synthesised and characterised by X-ray crystallography. In 1, the four copper(II) centres are linked by hydroxo bridges and the N1,N2-coordination of the deprotonated guanazole ligands. The core has considerably short Cu center dot center dot center dot Cu distances in the range of 3.3550(4)-3.3611(4) angstrom. Thermal analysis of 1 reveals that the cyclic framework constructed with hydroxo and guanazole ligands is stable up to 285 degrees C. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.