Complexes of doubly chelating ligands. Part IV. Nickel(II), zinc(II), magnesium(II), and uranyl(VI) complexes of L-β-(3,4-dihydroxyphenyl)-alanine (DOPA)

Abstract

The interactions of DOPA with nickel(II), zinc(II), magnesium(II), and uranyl(VI) ions in aqueous solution have been investigated at 25°± 0·01° and 1·0M-ionic strength (KNO₃) by potentiometric and spectrophotometric methods. The stoicheiometry and nature of the chelate reactions have been established and stability constants are reported for the nickel, zinc, and magnesium cases. Mixed metal complex systems have also been studied for the DOPA–uranyl–copper system. Interpretation of these systems was limited by precipitation and olation reactions of the complexes.