Nature of sulfur centered radicals formed during pulse radiolysis of 2-mercaptopyridine in aqueous solutions

In this: publication
By this: publisher
In this Subject: <a title="Physical & Theoretical Chemistry" href="/content/subcat?j_subject=169&j_availability=">Physical & Theoretical Chemistry
By this author: Naik, D.B. ;&nbsp; Kishore, K.

Authors: Naik, D.B.; Kishore, K.

Source: Research on Chemical Intermediates, Volume 28, Number 6, 2002 , pp. 603-617(15)

Buy & download fulltext article:

Price: $35.00 plus tax (Refund Policy)

Abstract:

Spectral, redox and kinetic properties of the transient species formed by the reaction of 2- mercaptopyridine (2-MPy) with oxidants such as OH, Br¯₂^. ; N^.₃ and Cl¯₂^. radicals and reductants such as e¯_aq, H-atoms and (CH₃)₂^.COH radicals have been studied by pulse radiolysis technique. Reaction of one-electron oxidants with 2-MPy at pH 11.5 led to the formation of 2-pyridyl thiyl radical. The reduction potential for the couple C₅H₄NS^. /C₅H₄NS¯ was estimated to be 0.84 V vs NHE from the equilibrium studies with I¯₂^./2I¯ couple. At pH 6.8, the reaction of N^.₃ radical with 2-MPy gave a cation radical derived from 2-MPy. At pH 6.8 and 11.5, OH radicals react with 2-MPy by addition pathway. Reaction of e¯_aq with 2-MPy was found to give a reducing radical capable of transferring electron to methyl viologen. At acidic pH, the reaction of (CH₃)₂^. COH radicals and H-atoms with 2-MPy gave transient species identical to those produced by the reaction of oxidising radicals, namely, OH radicals, Cl¯₂^. and Br¯₂^. radicals.

Document Type: Research article

DOI: http://dx.doi.org/10.1163/15685670260373362

Publication date: 2002-08-01