Mechanisms and product distribution of the O3-initiated degradation of (E)-2-heptenal, (E)-2-octenal and (E)-2-nonenal

BLANCO MARÍA BELÉN; BARNES, IAN; ELIZABETH GAONA COLMAN; MARIANO TERUEL

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Lugar: Washington; Año: 2017 vol. 121 p. 5147 - 5155

1089-5639

The O3-molecule initiated degradation of three2-alkenals (E)-2-heptenal, (E)-2-octenal, and (E)-2-nonenalhas been investigated in a 1080 L quartz-glass environmentalchamber at 298 ± 2 K and atmospheric pressure of syntheticair using in situ FTIR spectroscopy to monitor the reactantsand products. The experiments were performed in the absenceof an OH scavenger. The molar yields of the primary productsformed were glyoxal (49 ± 4) % and pentanal (34 ± 3) %from the reaction of (E)-2-heptenal with O3, glyoxal (41 ± 3)% and hexanal (39 ± 3) % from the reaction of (E)-2-octenalwith O3, and glyoxal (45 ± 3) % and heptanal (46 ± 3) %from the reaction of (E)-2-nonenal with O3. The residualbands in the infrared product spectra for each of the studiedreactions are attributed to 2-oxoaldehyde compounds. Based on the observed products, a general mechanism for the ozonolysisreaction of long chain unsaturated aldehydes is proposed, and the results are compared with the available literature data.