Acta Phys. -Chim. Sin. ›› 1986, Vol. 2 ›› Issue (06): 525-532.doi: 10.3866/PKU.WHXB19860608

• ARTICLE • Previous Articles     Next Articles


Cheng Hua; Hu Zhibin   

  1. Department of Chemistry; Beijing Normal University
  • Received:1985-04-13 Revised:1986-03-09 Published:1986-12-15

Abstract: This paper presents an experimental study on the electrochemical behavior of 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) at hanging mercury drop electrode in aqueous solution.
DTNB reduction processes have seen established by means of electrolytic reduction preparation, cyclic voltammetry, UV spectroscopy, IR-spectroscopy and ESR as well as electrochemical methods. It is proved that the disulfide bond (-S-S-) of DTNB is reduced to thiol group at the potential of the reduction wave. It is also confirmed that the nitro group of DTNB is liable to be reduced to amino group during electrochemical reduction. Hence, the final reduction product of DTNB is 5-thio-2-aminobenzoic acid. The carboxyl of DTNB is not likely to be reduced in electrochemical reduction. It has been suggested that DTNB is reduced according to ECE mechanism. The final product of DTNB is oxidizable in reverse cycllic scan. Experimental demonstrations and theoretical analysis of voltammogram giye the following mechanism: