H. Mohan
1990
Citations
0
Influential Citations
11
Citations
Journal
Journal of The Chemical Society-perkin Transactions 1
Abstract
The transient optical absorption band (λmax 390 nm, t½ 38 µs, Iµ 3.13 × 103 dm3 mol–1 cm–1) produced on pulse radiolysis of N2O-saturated aqueous solution of 3,3′-thiodipropionic acid (pH 6.0–10.0) has been assigned to intramolecular 3-electron-bonded species formed on p-orbital overlap of sulphur and oxygen. The absolute rate constant for the reaction of OH radicals forming a 390 nm band has been determined to be 1.1 × 1010 dm3 mol–1 s–1. An intermolecular dimer radical cation (λmax 500 nm, t½ 17 µs, Iµ 7.20 × 103 dm3 mol–1 cm–1) is formed on pulse radiolysis of an O2-saturated aqueous solution of 3,3′-thiodipropionic acid (pH 1.0–3.5, concentration >3.0 × 10–4 mol dm–3). Tl2+ and Cl2– are able to oxidize 3,3′-thiodipropionic acid with a bimolecular rate constant of 3.8 × 109 and 5.5 × 109 dm3 mol–1 s–1 respectively. The dimer radical cation of 3,3′-thiodipropionic acid (TDPA)2+˙, is able to oxidize I– to I2– with a bimolecular rate constant of 5.5 × 109 dm3 mol–1 s–1. An equilibrium is established between dimer radical cation (TDPA)2+˙ and Br– from which the one-electron redox potential for the TDPA +/TDPA couple has been determined to be 1.81 V versus normal hydrogen electrode (NHE).