CATION-EXCHANGE AND SPECTROPHOTOMETRIC STUDY OF COPPER(II)-CYCLOPOLYPHOSPHATE COMPLEXES

The stability constants of copper(II)-cyclopolyphosphate complexes were determined by the spectrophotometric and cation-exchange methods. For cyclohexa- and cyclooctaphosphate complexes, the stability constants by the above two methods did not agree. The stability constants determined by spectrophotometry were somewhat lower and depended on the wavelength measured. The definition of a constant molar absorption coefficient for the complex formed contains various problems. © 1990.