Theoretical study of the reaction mechanism of a series of 4-hydroxycoumarins against the DPPH radical

- DFT study of the antiradical mechanism of a series of 4-hydroxycoumarin derivatives.
- The most probable mechanism was HAT (gas or solution phase).
- The reaction paths show a pre-TS with an intermolecular bond.
- Observed behaviors are similar to those of phenols.
- The results provide a understanding of the H-abstraction of a no-phenolic hydroxyl.