Skip to content
Research Article Open access CC BY 4.0

Reduction of 3,7-Bis(dimethylamino) phenazothionium Chloride by Benzenethiol in Aqueous Nitric Acid Medium: A Mechanistic Approach

S. O. Idris, J. O. Suleman, J. F. Iyun, A. A. Osunlaja

Chemical Science International Journal · pp. 313–321 · Published 1 Jan 2015

10.9734/ACSJ/2015/11703

Abstract

The kinetics of the reduction of 3,7-bis(dimethylamino)phenazothionium chloride (MB+) by benzenethiol in aqueous solution has been investigated in the acid range 0.3≤[H+  ≤ 0.9 mole dm-3, ionic strength (µ) of the reaction medium in the range: 0.4 ≤ µ ≤ 1.0 mole dm-3 (NaNO3) and temperature, T = 29ºC. The reaction is first order in both [oxidant] and [reductant] and display an inverse order acid dependence with an overall reaction that conforms to the rate law:  [MB+]  = (Kk4[H+]-1 + k6)([MB+][ C6H5SH]) at [H+] = 0.3 mole dm-3 and µ = 1.0 mole dm-3 (NaNO3). The rate of the reaction increased with increase in the ionic strength and decrease in dielectric constant of the reaction medium. Added HCOO- and Cl- accelerated the rate of the reaction. Spectroscopic investigation did not reveal the formation of any stable reaction intermediate. Test for free radical was positive and a plausible mechanism consistent with these observations has been proposed.  

3,7-bis(dimethylamino)phenazothionium chloride benzenethiol kinetics stoichiometry Michaelis-Menten plot outersphere

References (15)

  1. 1 “Lest we forget you — methylene blue …” [DOI]
  2. 2 Photobleaching of methylene blue sensitised by TiO2: an ambiguous system? [DOI]
  3. 3 Kinetics and mechanism of color removal of methylene blue with hydrogen peroxide catalyzed by some supported alumina surfaces [DOI]
  4. 4 Kinetics of Methylene Blue Reduction by Ascorbic Acid [DOI]
  5. 5 Methylene Blue - Ascorbic Acid: An Undergraduate Experiment in Kinetics [DOI]
  6. 6 The Decay of Methylene Blue in Alkaline Solution [DOI]
  7. 7 Reduction of methylene blue by thiocyanate: Kinetic and thermodynamic aspects [DOI]
  8. 8 Hydrogen-ion dependence of reaction rates and mechanism [DOI]
  9. 9 Kinetics of the methylene blue oxidation by cerium(IV) in sulphuric acid solutions [DOI]
  10. 10 Bleaching of Methylene Blue by Hydrated Titanium Dioxide
  11. 11 Reduction mechanism of a coordinated superoxide by thiols in acidic media [DOI]
  12. 12 The Influence of Transition Metal Ions on the Kinetics of Ascorbic Acid Oxidation by Methylene Blue in Strongly Acidic Media
  13. 13 Kinetics and mechanisms of the electron-transfer reactions between uranium(III) and some ruthenium(III) ammine complexes [DOI]
  14. 14 Reactivity of Two Protolytic Forms of Methylene Blue in Reaction with Ascorbic Acid
  15. 15 STUDIES OF THE PHOTOCHEMICAL KINETICS OF METHYLENE BLUE WITH REDUCTANTS

Cited by 16

Degradation of Tolonium Chloride Dye by Phosphate Ion in Aqueous Acidic Solution: Kinetic Approach

Patricia Umoru, Mohammad Lawal, Oluwayemisi Abiodun Babatunde · Journal of the Turkish Chemical Society Section A: Chemistry · 2024

Application of charged micelle generators on the oxidation of metabisulphite ion by molybdenum-oxime complex: Piszkiewicz kinetic model

Ikechukwu Ugbaga Nkole, Sulaiman Ola Idris, Ibrahim Abdulkadir · Progress in Reaction Kinetics and Mechanism · 2025

Oxidation and Reduction

R. N. Mehrotra · Organic Reaction Mechanisms Series · 2019

Showing 7 of 16 known citations — external sources report more than can currently be individually listed.

Article metrics

Real usage data collected on this platform.

14

Page views

0

PDF downloads

1

Outbound clicks

16

Citations

Views over time

Views by country

Approximate, from request IP at view time — not citizenship or institution. Countries with fewer than 5 views are grouped as "Other".

Traffic sources

Referring site, by host.

Views and downloads exclude known bots/crawlers. Citations combines this platform's own DOI-resolved index with each external source's own reported total — see Cited by above for individually listed citing works. Last refreshed 0 seconds ago.