A sugar's choice: coordination to a mononuclear or a dinuclear copper(II) complex?
We proposed a decisive role of the number of metal ions at the sugar binding site for carbohydrate-coordinating copper(II) complexes. To verify this hypothesis, we studied the binding of the representatively chosen carbohydrates D-ribose (7), D-mannose (8), D-glucose (9), and D-maltose (10) to structurally related mono- and dinuclear copper(II) complexes in alkaline solution. All carbohydrates coordinate to the metal complexes in a 1:1 molar ratio. Coordination of 7 or 8 to the dinuclear copper(II) complex 1 is about 0.5 order of magnitude stronger than the complex formation with related mononuclear complexes. On contrast, 9, which is an epimer of 8, coordinates stronger to either one of the mononuclear copper(II) complexes in alkaline aqueous solution.
Striegler
Susanne
S
Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA. susanne.striegler@auburn.edu
Dittel
Michael
M
D002241:Carbohydrates / Q000737:chemistry*; D002413:Cations, Divalent; D003300:Copper / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008320:Maltose / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds; D012266:Ribose / Q000737:chemistry; D012996:Solutions
D002241:Carbohydrates; D002413:Cations, Divalent; D009942:Organometallic Compounds; D012996:Solutions; D012266:Ribose; D008320:Maltose; D003300:Copper; D005947:Glucose; D008358:Mannose