Synthesis,Crystal Structure and Magnetism Study on a Two-Dimensional Cu(II) Coordination Polymer with 2,5-Dimethylpyrazine-l,4-dioxide as Bridging Ligand

摘要

For a long time the field of molecular magnetism has attracted considerable attention,and major advances have been made in both their theoretical description and application as new molecular-based materials [1].In order to obtain strong magnetic coupling,judicious choice of coordinated atoms with large electron densities is a crucial factor.The theoretical calculation has confirmed that the electron densities on O atom from aromatic N-oxides are larger than those of the N atom from the relevant N-containing heteroaromatics [2].Pyrazinel,4-dioxide (pzdo) and its derivatives just belong to this kind of bridging ligands and its O-donor atoms possess larger electron density than that of the N-donor atom of pyrazine and its derivatives,and it led to the strong magnetic interactions in the 3D complex [Mn(N3)2(pzdo)]n containing pyrazine-1,4-dioxide as bridging ligand [3].To the best of our knowledge,among the reported complexes dealing with pyrazine-1,4-dioxide and its derivatives as bridging ligands,it includes binuclear Mn(II) complex [4],1D Mn(II) complex [4],2D Mn(II) and 2D Co(II) complexes [4,5],3D Co(II) complexes [6] and 3D rare earth complexes [8],but no Cu(II) complex has been published.Interest in the magneto-structure studies of multi-nuclear complexes with pyrazine- 1,4-dioxide and its derivatives as bridging ligands resulted in synthesis,characterization and magnetic study of the title complex.In this paper we present the crystal structure and the magnetic study of the two-dimensional sheet complex {[Cu(mu1,5-dmpzdo)2(H2O) (ClO4)] centre dot (ClO4) centre dot 2H2O}n (dmpzdo = 2,5-dimethylpyrazine-l,4-dioxide).