title: Ni(II) complexes with Schiff bases derived from amino sugars.
abstract: It was found by 1H and 13C NMR spectroscopy that the Schiff base, 2-deoxy-2-(2-hydroxybenzaldimino)-D-glucopyranose exhibits enol-imine-keto-amine and anomeric equilibria in methanolic, and in dimethyl sulfoxide solutions. The reaction of the Schiff base with nickel acetate gave the bidentate, mononuclear Ni(II) complex that was characterized by spectroscopic methods and by cyclic voltammetry. The coordination of the Schiff base to the metal is through the enol-imine tautomeric form, and the anomeric equilibrium remains in dimethyl sulfoxide solutions. This complex was also obtained by reaction of D-glucosamine with Ni(II) salicylaldehydate. The same reaction was employed for the synthesis of bis-N-[2-deoxy-D-galactopyranosyl-2-(2-hydroxybenzaldiminate)]Ni(II). The small paramagnetic shifts of the 1H NMR resonances of the complexes suggest that paramagnetic species are present in low proportions.
authors.affiliation: Facultad de Química y Biologi;a, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile.
authors.forename: Juan
authors.initials: J
authors.lastname: Costamagna
authors.forename: Luis E
authors.initials: LE
authors.lastname: Lillo
authors.forename: Betty
authors.initials: B
authors.lastname: Matsuhiro
authors.forename: Miguel D
authors.initials: MD
authors.lastname: Noseda
authors.forename: Manuel
authors.initials: M
authors.lastname: Villagrán
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000606:Amino Sugars / Q000737:chemistry*; D004563:Electrochemistry; D005688:Galactosamine / Q000737:chemistry; D005944:Glucosamine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D000606:Amino Sugars; D009942:Organometallic Compounds; D012545:Schiff Bases; C013243:salicylaldehyde; D005688:Galactosamine; D009532:Nickel; D005944:Glucosamine