The reaction mechanism of the α-H and β-H abstractions from 1-pentanol by OH radical has been studied using density functional theory at the B3LYP/6-31G(d) level. The geometries of the stationary points were optimized, and the harmonic vibration frequencies were calculated. The detailed profiles of the free energy surfaces for the reactions were constructed. The calculation results show that the main products of the α-H and β-H abstraction-initiated channels are 1-pentanal and 1-butanal, respectively. All the products from the two reaction channels can contribute to the formation of secondary organic aerosol through nucleation, hydration or absorption since their polarity and water-solubility are enhanced.

Key words: 1-pentanol, reaction mechanism, unimolecular decomposition, isomerization