Interaction of metal ions with disubstituted purines

The interaction of Cu(II), Ni(II), Zn(II), Co(II), Mn(II), Mg(II) and Ca(II) ions with disubstituted purines as 2 : 6 diaminopurine, 2-amino 6-mercaptopurine and 2-mercapto 6-aminopurine and 8-azaadenine has been investigated by a potentiometric method. The stability constants of the complexes containing a 1 : 1 ratio of the ligand to the metal ions have been reported at 45° and 0·10 M KNO3 ionic strength. © 1973.