A potentiometric and spectroscopic study of copper(II) diaminodioxime complexes

Copper(II) and H+ complexes of 3,3,8,8-tetramethyl-4,7-diazadecane-2,9-dione dioxime, 3,3,9,9-tetramethyl-4,8-diazaundecane-2, 10-dione dioxime and 3,3,10,10-tetramethyl-4,9-diazadodecane-2, 11-dione dioxime have been studied at 25 degrees C and ionic strength 0.15 mol dm(-3) NaCl, using glass-electrode potentiometry. Electronic spectra have been used to postulate structures for the different species in solution. In each case the metal binds to the four nitrogen atoms of the oxime. In the MLH(-1) species hydrogen bonding between the terminal oxime groups produces a pseudo-macrocycle. Computer simulation has been used to predict the effect of the ligands on the blood-plasma metal-ion distribution in vivo.