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Monatshefte für Chemie / Chemical Monthly

, Volume 119, Issue 4, pp 429–438 | Cite as

Mechanism of the voltammetric reduction of phenolphthalein at the mercury electrode inDMF

  • Refat Abdel-Hamid
Anorganische Und Physikalische Chemie

Abstract

The electrochemical reduction of phenolphthalein in dimethylformamide solution containing 0.1 mol dm−3 tetraethylammonium perchlorate at the hanging dropping mercury electrode showed an irreversible two-electron voltammetric peak. It was found that the CV peak is diffusion-controlled at low concentrations (⩽0.4 mmol dm−3). At higher concentration (⩾0.5 mmol dm−3) a postpeak was developed besides the diffusion-controlled one which was assigned to the adsorbed depolarizer. Cyclic voltammetric studies indicate that phenolphthalein follows an ECEC mechanism. Convolution and deconvolution potential sweep voltammetry confirm that mechanism.

Keywords

Dimethylformamide Electrochemical reduction Cyclic voltammetry Convolution and deconvolution voltammetry ECEC mechanism 

Mechanismus der voltametrischen Reduktion von Phenolphthalein an der Quecksilberelektrode inDMF

Zusammenfassung

Die elektrochemische Reduktion von Phenolphthalein an der tropfenden Quecksilberelektrode in Dimethylformamidlösung mit einem Gehalt von 0.1 mol dm−3 an Tetraethylammoniumperchlorat zeigte ein irreversibles voltametrisches Maximum für zwei Elektronen. Es zeigte sich, daß der CV-Peak bei niederen Konzentrationen (⩽0.4 mmol dm−3) diffusionskontrolliert ist. Bei höheren Konzentrationen (⩾0.5 mmol dm−3) entwickelte sich ein nachkommendes Maximum neben dem diffusionskontrollierten, welches dem adsorbierten Depolarisator zugeordnet wurde. Untersuchungen mittels cyclischer Voltametrie zeigten, daß Phenolphthalein einem ECEC-Mechanismus folgt. Konvolutions-und Dekonvolutions-Potential-Sweep-Voltametrie bestätigten diesen Mechanismus.

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Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • Refat Abdel-Hamid
    • 1
  1. 1.Department of Chemistry, Faculty of ScienceSohag UniversitySohagEgypt

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