Voltammetry of Electroinactive Species Using Quinone/Hydroquinone Redox: A Known Redox System Viewed in a New Perspective
✍ Scribed by Mohammad Rafiee; Davood Nematollahi
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 287 KB
- Volume
- 19
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
Abstract
Electrochemical behavior of p‐benzoquinone (Q), hydroquinone (H~2~Q) and quinhydrone complex (QH) have been investigated in aqueous unbuffered solutions. The results revealed that in unbuffered solution the half wave potential of hydroquinone has a significant difference with quinone's half wave potential. It shown that, added acid in an unbuffered solution of Q, give rise to a new reduction peak at a more positive potential than original reduction peak of Q. The half‐peak potential of this new peak is dependent on acidity of added acid (pK~a~) and its height is proportional to the acid concentration. Also, added base in an unbuffered solution of H~2~Q, give rise to a new oxidation peak at a more negative potential than original oxidation peak of H~2~Q. The half‐peak potential of this new peak is dependent on basicity of added base (pK~b~) and its height is proportional to the base concentration. This paper shows new perspectives for a known system in aqueous unbuffered solutions, by means of voltammetric responses that can be exploited for the electrochemical investigation of non electroactive species such as HPO$\rm{ _4^{2 - } }$, HCO$\rm{ _3^ - }$ or CH~3~COOH.