First synthesis and characterization of zinc(II) complexes containing N-glycosides derived from ethylenediamine and D-glucosamine

Zinc(II) complexes containing N-glycosides derived from D-glucosamine (D-GlcN) and ethylenediamine ten), [Zn(D-GlcN-en)(2)]X-2 (1a X = Cl, 1b X-2 = SO42-), were prepared and characterized by elemental analysis and nuclear magnetic resonance spectroscopy involving X-ray crystallography, where D-GlcN-en = 1 -{(2-aminoethyl)amino}-2-amino-1,2-dideoxy-D-glucose. The complex cation of la has a nearly C-2 symmetry and the central zinc atom is octahedrally coordinated by two tridentate N-glycoside ligands from D-glucosamine and ethylenediamine. The N-glycoside ligand, D-GlcN-en, ligates to the zinc atom through the C-2 amino nitrogen atom of D-glucosamine and the two nitrogen atoms of the diamine in a meridional mode. The analysis of the solution conformation of the sugar ring in la based on vicinal coupling constants confirmed the similar structure revealed by X-ray crystallography.