Electron transfer reaction of Tris(1,10-phenanthroline) cobalt(III) complex [Co(phen)3]3+ and thiosulphate ion (S2O32âˆ’) in an aqueous acidic medium

C R. Osunkwo; I U. Nkole; A D. Onu; S O. Idris

doi:10.14419/ijac.v6i1.11326

Article Details

Electron transfer reaction of Tris(1,10-phenanthroline) cobalt(III) complex [Co(phen)3]3+ and thiosulphate ion (S2O32âˆ’) in an aqueous acidic medium

Authors:

C R. Osunkwo | I U. Nkole | A D. Onu | S O. Idris

Publisher:

Science Publishing Corporation

Journal:

International Journal of Advanced Chemistry Vol.6 Issue 1, pp.121-126

Document Type:

Article

Publication Date:

12/2018

Document Language:

English

Document ID (Org No.):

2001385691

pISSN:

2310-2977

DOI:

10.14419/ijac.v6i1.11326

Keywords:

Complex

Abstract:

 The electron transfer reaction of Tris (1,10-phenanthroline)cobalt(III) complex by thiosulphate ion has been studied in an aqueous acidic medium. Stoichiometric determination shows that for one mole of the oxidant that was reduced, one mole of the reductant was consumed; the reaction conforms to an overall equation:Â 2[Co(phen)3]3+ + 2S2O32âˆ’ â†’ 2[Co(phen)3]2+ + S4O62âˆ’Â Kinetics study carried out under pseudo-first order condition shows that the reaction proceeded via a one-way acid-dependent pathway and was third order overall; zero order with respect to the oxidant concentration, second order with respect to the reductant concentration and first order with respect to the hydrogen ion concentration. The empirical rate law conforms to the equation:Â âˆ’ Â  {Co(phen)3}3+] = a [H+] [S2O32âˆ’]2Â â€˜aâ€™ = 128.26 dm6 molâˆ’2 sâˆ’1: at [H+] = 2.0 Ã— 10âˆ’2 mol dmâˆ’3, Âµ = 0.4 mol dmâˆ’3 (NaCl), T = 28 Â± 1ËšC and Î»max = 495 nm.The rate of reaction increased at the increase in ionic strength and at the decrease in medium dielectric constant. Added cations and anions catalyzed and inhibited the reaction rates respectively. The Michaelis-Menten plot of 1/k1 versus 1/[S2O32âˆ’]2 started from the origin. Hence based on spectroscopic investigation, thermodynamic information from temperature dependence studies and kinetic evidence from Michaelisâ€“Menten plots and the interactions with added ions, an outer-sphere mechanism has been rationalized for this reaction. The mechanistic scheme of the reaction was proposed via the stated mechanistic route.Â Â Â.

Article Details

Electron transfer reaction of Tris(1,10-phenanthroline) cobalt(III) complex [Co(phen)3]3+ and thiosulphate ion (S2O32âˆ’) in an aqueous acidic medium

Authors: C R. Osunkwo | I U. Nkole | A D. Onu | S O. Idris

Publisher: Science Publishing Corporation

Journal: International Journal of Advanced Chemistry Vol.6 Issue 1, pp.121-126

Document Type: Article

Publication Date: 12/2018

Document Language: English

Document ID (Org No.): 2001385691

pISSN: 2310-2977

DOI: 10.14419/ijac.v6i1.11326

Complex

Issues

Authors:

C R. Osunkwo | I U. Nkole | A D. Onu | S O. Idris

Publisher:

Science Publishing Corporation

Journal:

International Journal of Advanced Chemistry Vol.6 Issue 1, pp.121-126

Document Type:

Article

Publication Date:

12/2018

Document Language:

English

Document ID (Org No.):

2001385691

pISSN:

2310-2977

DOI:

10.14419/ijac.v6i1.11326