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

The title polymeric complex [Cu(C 4H 2O 4)(C 10H 8N 2)] n·2nH 2O was prepared and its crystal structure was determined by X-ray diffraction methods. The crystal belongs to space group P2 1/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 plane. Adjacent chains link to each other by H-bonding between carboxyl groups and crystalline water. The distance of 0.3482 nm between parallel bipyridine rings shows a π-π stacking interaction. The title complex was also characterized by IR, UV and ESR spectra.