Interfacial vs Bulk Ozonolysis of Nerolidol

Abstract

Ozone readily reacts with olefins with the formation of more reactive Criegee intermediates (CIs). The transient CIs impact HO x cycles, and they play a role in new particle formation in the troposphere. Oxidation by O3 occurs both in the gas-phase, in the liquid phase, and at air–water and air–aerosol interfaces. In light of the importance of O3 in environmental and engineered chemical transformations, we have investigated the ozonolysis mechanisms of a triolefin C15-alcohol, nerolidol (Nero, a biogenic sesquiterpene), at the air–water interface in the presence of acetonitrile. Surface-sensitive pneumatic ionization mass spectrometric detection of α-hydroxy-hydroperoxides and functionalized carboxylates, generated by the hydration and isomerization of CIs, respectively, enables us to evaluate the relative reactivity of each C=C toward O3. In addition, we compare bulk-phase ozonolysis chemistry to similar reactions taking place at the air–water interface. Our experimental results show that O3 reacts primarily with the (CH3)2C=CH– and −(CH3)­C=CH– moieties (>∼98%), while the O3 attack on the terminal −HC=CH2 site (<∼2%) is a minor pathway during both interfacial and bulk ozonolysis. The presence of functionalized-carboxylates on interfaces but not in bulk-phase reactions with O3 indicates that the isomerization of the CIs is not hindered at the air–water interface due to the lower availability of water .

Water Dramatically Accelerates the Decomposition of α-Hydroxyalkyl-Hydroperoxides in Aerosol Particles

“…The experimental method for bulk ozonolysis has been described elsewhere 63 and is only briefly mentioned here. Figure S1 shows a schematic diagram of our experimental procedure for preparing α-HHs in solvent mixtures.…”

Photoinduced Oxidation Reactions at the Air–Water Interface

“…The reaction rate acceleration can stem from an increase in reactant concentration (molecular crowding) or the stabilization of a transition state (or a combination of both); however, a full understanding of this mechanism remains lacking. The enhancement of redox reactions has been broadly studied in this context, with prominent examples including H-abstraction by OH, ozonolysis − and ozonations, Fenton and Fenton-like reactions, Dakin and Baeyer–Villiger oxidations, halide anion oxidation by OH and O 3 , and the spontaneous formation of hydrogen peroxide and spontaneous reduction of organic molecules at the neat water surface.…”

Single-particle Raman spectroscopy for studying physical and chemical processes of atmospheric particles

“…Probing heterogenous reactions on the particle surface is possible via ES-SERS, TERS, and normal Raman imaging. As particle constituents can be unevenly distributed (e.g., in LLPS) within a single particle, chemistry may not be the same between the bulk and the surface layers (Wei et al, 2018;Olson et al, 2019;Qiu et al, 2019;Q. Huang et al, 2021;Lam et al, 2021).…”