UV absorption spectra of trans-2-pentenal, trans-2-hexenal and 2-methyl-2-pentenal

Abstract

C5 and C6 unsaturated aldehydes are a category of BVOCs released by plants in response to their wounds and stress. In this work, the gas phase UV absorption spectra of trans-2-pentenal (t-2P), trans-2-hexenal (t-2H) and 2-methyl-2-pentenal (2M2P) are determined between 240 and 400 nm, at room temperature and at pressures (1–9) torr. The reported UV absorption cross sections are (cm2molecule−1): σt-2P, 330 = (4.86 ± 0.53) × 10−20, σt-2H, 330 = (5.43 ± 0.57) × 10−20 and σ2M2P, 320 = (6.62 ± 0.50) × 10−20. Their photolysis constants as well as their atmospheric lifetimes toward photolysis were then estimated.