CRYSTAL AND MOLECULAR-STRUCTURE OF TETRA-MU-N-ACETYLGLYCINATODIAQUODICOPPER(II)

The crystal structure of binuclear copper(II) N-acetylglycinate monohydrate, [Cu(OOCCH2NH- COCH3)2(H2O)]2 was determined by three-dimensional X-ray diffraction studies. The compound crystallizes in the monoclinic system with the space group P21/c. The cell parameters are a = 7.288(2), b = 8.892(2), c = 19.473(3) Å, β = 103.04(3)°, V = 1229.5 Å3, Z = 4, dc = 1.695 and dm = 1.69 g cm-3. Full-matrix least-squares refinement using 2059 independent reflections has reached the R value of 0.041. The two copper atoms in the molecule are held together in a dimeric unit by the four carboxylate groups, and each copper atom is further bonded to a water molecule, resulting in a square pyramidal geometry. The mean CuO(carboxylate), CO- (water) and CuCu distances are 1.971(3), 2.108(3) and 2.666(1) Å, respectively. Hydrogen bonding is observed between the peptide-NH and the carboxylate groups, and the peptide-CO groups and the water molecules. © 1979.