177316-72-2Relevant articles and documents
Aerosol formation from the reaction of α-pinene and ozone using a gas- phase kinetics-aerosol partitioning model
Kamens, Richard,Jang, Myoseon,Chien, Chao-Jung,Leach, Keri
, p. 1430 - 1438 (1999)
As a result of new aerosol compositional information, we have implemented an exploratory model for predicting aerosol yields from the reaction of α-pinene with ozone in the atmosphere. This new approach has the ability to embrace a range of different atmospheric chemical conditions, which bring about biogenic aerosol formation. A kinetic mechanism was used to describe the gas-phase reactions of α-pinene with ozone. This reaction scheme produces low vapor pressure reaction products that distribute between gas and particle phases. Some of the products have subcooled liquid vapor pressures which are low enough to initiate self-nucleation. More volatile products such as pinonic acid and pinonaldehyde will not self-nucleate but will partition onto existing particle surfaces. Partitioning was treated as an equilibrium between the rate of particle uptake and rate of particle loss of semivolatile terpene reaction products. Given estimated liquid vapor pressures and activation energies of desorption, it was possible to calculate gas-particle equilibrium constants and aerosol desorption rate constants at different temperatures. This permitted an estimate of the rate of absorption from the gas phase. Gas- and aerosol-phase reactions were linked together in one chemical mechanism, and a chemical kinetics solver was used to predict reactant and product concentrations over time. Aerosol formation from the model was then compared with aerosol production observed from outdoor chamber experiments. Approximately 20-40% of the reacted α-pinene carbon appeared in the aerosol phase. Models vs experimental aerosol yields are shown in Figure 2 and illustrate that reasonable predictions of secondary aerosol formation are possible. The majority of the aerosol mass came from the mass transfer of gas-phase products to the aerosol phase. An important observation from the product data and the model was that as temperatures and aerosol mass changed from experiment to experiment, the composition of the aerosol changed. An exploratory model for predicting aerosol yields from the reaction of α-pinene with ozone in the atmosphere was implemented. A kinetic mechanism was used to describe the gas-phase reactions of α-pinene and ozone. This reaction scheme produces low vapor pressure reaction products that distribute between gas and particle phases. Gas- and aerosol-phase reactions were linked together in one chemical mechanism, and a chemical kinetics solver was used to predict reactant and product concentrations over time. Approximately 20-40% of the reacted α-pinene carbon appeared in the aerosol phase. The majority of the aerosol mass came from the mass transfer of gas-phase products to the aerosol phase.
Oxodealkenylative Cleavage of Alkene C(sp3)?C(sp2) Bonds: A Practical Method for Introducing Carbonyls into Chiral Pool Materials
Smaligo, Andrew J.,Wu, Jason,Burton, Nikolas R.,Hacker, Allison S.,Shaikh, Aslam C.,Quintana, Jason C.,Wang, Ruoxi,Xie, Changmin,Kwon, Ohyun
supporting information, p. 1211 - 1215 (2019/12/12)
Reported herein is a one-pot protocol for the oxodealkenylative introduction of carbonyl functionalities into terpenes and terpene-derived compounds. This transformation proceeds by Criegee ozonolysis of an alkene, reductive cleavage of the resulting α-alkoxy hydroperoxide, trapping of the generated alkyl radical with 2,2,6,6-tetramethylpiperidin-1-yl (TEMPO), and subsequent oxidative fragmentation with MMPP. Using readily available starting materials from chiral pool, a variety of carbonyl-containing products have been accessed rapidly in good yields.
Mechanisms for the formation of secondary organic aerosol components from the gas-phase ozonolysis of α-pinene
Ma, Yan,Russell, Andrew T.,Marston, George
, p. 4294 - 4312 (2008/12/22)
Gas-phase ozonolysis of α-pinene was studied in static chamber experiments under 'OH-free' conditions. A range of multifunctional products-in particular low-volatility carboxylic acids-were identified in the condensed phase using gas chromatography coupled to mass spectrometry after derivatisation. The dependence of product yields on reaction conditions (humidity, choice of OH radical scavengers, added Criegee intermediate scavengers, NO2etc.) was investigated to probe the mechanisms of formation of these products; additional information was obtained by studying the ozonolysis of an enal and an enone derived from α-pinene. On the basis of experimental findings, previously suggested mechanisms were evaluated and detailed gas-phase mechanisms were developed to explain the observed product formation. Atmospheric implications of this work are discussed. the Owner Societies.
Identification of products containing -COOH, -OH, and -C=O in atmospheric oxidation of hydrocarbons
Yu, Jianzhen,Flagan, Richard C.,Seinfeld, John H.
, p. 2357 - 2370 (2007/10/03)
Atmospheric oxidation of hydrocarbons by hydroxyl radicals and ozone leads to products containing -COOH, -OH, and -C=O functional groups. The high polarity of such compounds precludes direct GC-MS analysis. In addition, many such compounds often exist in a single sample at trace levels. An analytical method has been developed to identify compounds containing one or more functional groups of carbonyl, carboxy, and hydroxy in atmospheric samples. In the method, -C=O groups are derivatized using O-(2,3,4,5,6- pentafluorobenzyl) hydroxy amine (PFBHA), and -COOH and -OH groups are derivatized using a silylation reagent N,O-bis(trimethylsilyl)- trifluoroacetamide (BSTFA). The derivatives are easily resolved by a GC column. The chemical ionization mass spectra of these derivatives exhibit several pseudomolecular ions, allowing unambiguous determination of molecular weights. Functional group identification is accomplished by monitoring the ions in the electron ionization mass spectra that are characteristic of each functional group derivative: m/z 181 for carbonyl and m/z 73 and 75 for carboxyl and hydroxy groups. The method is used to identify products in laboratory studies of ozone oxidation of α-pinene and Δ3-carene. Among products from ozone oxidation of α-pinene, we have detected pinonaldehyde, norpinonaldehyde, pinonic acid, norpinonic acid, C10 hydroxy dicarbonyls, pinic acid, 2,2-dimethyl-3-(formylmethyl)-cyclobutane-formic acid, and a product that has a molecular weight of 156 and contains a C=O and a COOH/OH group. The latter two products have not been reported previously. Δ3- Carene is structurally analogous to α-pinene in that both have an internal unsaturated bond where ozone oxidation takes place. We have also identified the corresponding analogous products, of which all but caronaldehyde are reported for the first time. An analytical method was developed to identify compounds containing one or more functional groups of carbonyl, carboxyl and hydroxyl in atmospheric samples. -C-to-O double bond groups are derivatized using 0-(2,3,4,5,6-pentafluorobenzyl)hydroxyl amine, and -COOH and -OH groups are derivatized using a silylation reagent N,O-bis(trimethylsilyl)-trifluoroacetamide. The derivatives are resolved using a gas chromatography column coupled with mass spectrometry. The method identified products in laboratory studies of ozone oxidation of α-pinene and Δ3-carene.
Radical chemistry based on (+)-cis-pinononic and (+)-cis-pinonic acids
Barton, Derek H. R.,Fontana, Giovanni
, p. 1953 - 1968 (2007/10/03)
A high yield method for the preparation of (+)-cis-pinononic acid starting from the inexpensive (+)-α-pinene has been developed. The capture of the cyclobutyl radical from decarboxylation of (+)-cis-pinonic acid has been investigated. Moreover the radical
