Complex formation between copper(II) and several b-amino alcohols in aqueous solution: a potentiometric and spectrophotometric study

The behaviour of solutions containing copper(II) and several b-amino alcohols was examined by potentiometric and spectrophotometric techniques. The potentiometric results at 258C and KNO 0.5 M, indicates in all the examined systems the formation of four 3 main species with M:L:H stoichiometry 1:1:0, 1:1:21, 1:2:21 and 1:2:22, respectively. The deprotonated species have been demonstrated to be alkoxo chelates formed by the loss of alcoholic hydrogen. No evidence of formation of ternary hydroxy or polynuclear complexes have been found in the examined experimental conditions, and the absence of dimeric alkoxo-bridged species have been confirmed by the analysis of the UV charge-transfer bands. The dependence of complex stability on the ligand structure is discussed with particular regard to the influence exherted by the number of hydroxyl groups. Also, the comparison with the behaviour of other metal ions is discussed.