Further studies on the synergistic effect of Ni(II) and Co(II) ions on the sulfite induced autoxidation of Cu(II) penta and hexaglycine complexes

Journal of the Brazilian Chemical Society

Luciana B. Carvalho¹  María V. Alipázaga¹  Rubén G. M. Moreno¹  Nina Coichev¹ 

[1] ,Universidade de São Paulo Instituto de Química São Paulo SP ,Brazil

关键词: cooper;    nickel;    cobalt;    pentaglycine;    hexaglycine;    sulfite;   

DOI  :  10.1590/S0103-50532007000600021

来源: SciELO

【 摘 要 】

The autoxidation of Cu(II)/penta and hexaglycine complexes at pH = 9 is very slow showing a large induction period (about 4 h). The presence of S(IV) practically does not affect the rate of this reaction. Addition of small amounts of Ni(II) or Co(II) increases significantly the reaction rate and the effectiveness of Cu(III) formation, the induction period becomes as short as 0.5 s. The observed rate constant for Cu(III) formation also depends on the S(IV) concentration. The mechanism is discussed based on the available literature information and involves a radical chain and redox cycling of the metal ion complexes.

【 授权许可】

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