Radical scavenging activity of sterically hindered catecholate and o-amidophenolate complexes of LSbVPh3 type

The radical scavenging effect of the substituted catecholates (1–3, 6) and o-amidophenolates (4, 5) of triphenylantimony(V) in reactions with DPPH• radical and in a process of oleic acid peroxidation was studied in details. Complexes 1–6 show the high activity in radical scavenging reactions with DPPH• radical leading to disappearance of radical species. Complexes were demonstrated to be high-efficient inhibitors of chain-radical process of the peroxidation of oleic acid as well as the effective destructors of the formed hydroperoxides. It was found that the effectiveness of complexes studied in the inhibition of the peroxidation of oleic acid depends on the first oxidation potential of complex.

Graphical abstractCatecholato and o-amidophenolato triphenylantimony(V) complexes show the high radical scavenging effect in reactions with DPPH• radical and in a process of oleic acid peroxidation. Complexes serve as high-efficient inhibitors of chain-radical peroxidation process as well as the effective destructors of hydroperoxides. Reversible dioxygen binding by complexes at low temperature allows to decrease a local oxygen concentration to prevent chain propagation.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Complexes Ph3Sb(Cat) and Ph3Sb(AP) were examined on the radical scavenging effect. ► Complexes are high-efficient inhibitors of chain-radical peroxidation process. ► The inhibiting activity depends on the oxidation potential of redox-active ligands. ► Triphenylantimony(V) catecholates are able to destruct effectively hydroperoxides.