Details

Autor(en) / Beteiligte

• Matsui, Yoshihisa
• Kinugawa, Kohji

Titel

Spectrophotometric and Polarimetric Investigations on Complex Formation between Copper(II) and Cyclodextrins in an Alkaline Solution

Ist Teil von

• Bulletin of the Chemical Society of Japan, 1985-10, Vol.58 (10), p.2981-2986

Ort / Verlag

Tokyo: The Chemical Society of Japan

Erscheinungsjahr

1985

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Copper(II) forms a 1 : 1 complex (CuCD), as well as a 2: 1 complex (Cu2CD), with cyclodextrin (CD) in an alkaline solution. An equilibrium constant (Kdsp) for the disproportionation reaction of Cuα-CD to Cu2α-CD and α-CD was determined by spectrophotometry and polarimetry to be ca. 17 in 1.0 mol dm3 NaOH at 25 °C. The Kdsp value gradually decreased with increasing NaOH concentration. A ligand-exchange reaction of CU2CD with ethylenediaminetetraacetic acid (EDTA) to give Cu(edta)2− and CD was also examined by means of spectrophotometry and polarimetry. The equilibrium constants (Klex) for the ligand-exchange reaction was evaluated to be ca. 2.1 for an α-CD system and ca. 1.2 for a β-CD system in 1.0 mol dm−3 NaOH at 25 °C. The Klex value decreased rapidly with increasing NaOH concentration. The role of OH− in the complexation of Cu(II) with CD is discussed on the basis of these results.