Antioxidant Activities of Monosubstituted Indolinonic Hydroxylamines: A Thermodynamic and Kinetic Study.

Indolinonic hydroxylamine (IH) is known as a potential artificial antioxidant in apolar environments. Here, a library of 108 monosubstituted derivatives was screened in silico to identify a lead compound for increased antioxidant activity, following a strategy of shortlisting based on thermochemical and kinetic properties. It was found that the presence of substituents at the 2, 4, and 7 positions increased, while substituents in other positions decreased the BDE(O-H) values, in good correlation to the electron-donating ability of substituents. Among the studied compounds, the N and 5 amine-substituted derivatives have the lowest BDE(O-H) values (62.4-64.0 kcal mol