The tripotassium salt of tris(2,3,5,6-tetrachloro-4-hydroxysulfonylphenyl) methyl radical (3 K+ TSPTM3-) reacts in water with hydroxyl radical very fast with a rate constant (k = 2.4 × 1011 M-1 s-1) much higher than that of the reaction of hydroxyl radical with the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) (k = 3.4 × 109 M-1 s-1). The reaction affects the radical character of the molecule and is monitored by electron paramagnetic resonance (EPR). The hydroxyl radical scavenging is established by the characterization of the resulting water-soluble product as the dipotassium salt of 4-[bis(2,3,5,6-tetrachloro-4-hydroxysulfonylphenyl)methylene]-2,3,5,6- tetrachlorocyclohexa-2,5-dien-1-one (2). © 2013 The Royal Society of Chemistry.

Financial support for this research from the Spanish Ministry of Science and Innovation through projects AGL2009-12374- C03-03/ALI and CTQ2009-13797 is gratefully acknowledged. J.A.M. gratefully acknowledges the Spanish Foreign Office Department for a pre-doctoral grant (AECI).

Peer Reviewed