Synthesis,Characterization and Crystal Structure of （2,2′—Bipyridine）（μ—maleato）copper（II）Dihydrate

The title polymeric complex [Cu(C4H2O4)(C10H8N2)]n·2nH2O was prepared and its crystal structure was determined by X-ray diffraction methods.The crystal belongs to space group P21/c with cell dimensions of a=1.0104(1),b=1.9952(2),c=0.7357(2)nm,β=98.38(2)° and Z=4.The complex forms zig-zag chains along crystallographic axis c via Cu-O (carboxyl) bond in the apical direction.Each repeated unit consists of a square pyramidal Cu(Ⅱ） centre with one maleate dianion and one 2,2′-bipyridine forming a basal phane.Adjacent chains link to each other by H-bonding between carboxyl groups and crystalline water.The distance of 0.3482 nm between parallel bipyridline rings shows a π-π stacking interaction.The title complex was also characterized by IR,UV and ESR spectra.