Dissociation mechanism of the 3-hydroxypyridine radical cation: A computational study

The potential energy surface (PES) for the losses of CO and HCN from the 3-hydroxypyridine radical cation (3-HP^+•) and for the isomerizations to 2- and 4-HP^+• was determined from G3//B3LYP calculations. The overall activation energies are similar for six dissociation channels to form the radical cations of CH₂=CHCH=N=CH, 1-H, 2-H, and 3-H pyrrole by the loss of CO to form the radical cations of CH₂=CHCH=C=O and furan by the loss of HCN. A kinetic analysis based on the obtained PES shows that the acyclic C₄H₅N^+• and C₄H₄O^+• ions are the main products formed by the losses of CO and HCN, respectively.