Exploring Conditions for Ultrafine Particle Formation from Oxidation of Cigarette Smoke in Indoor Environments.

Cigarette smoke is an important source of particles and gases in the indoor environment. In this work, aging of side-stream cigarette smoke was studied in an environmental chamber via exposure to ozone (O), hydroxyl radicals (OH) and indoor fluorescent lights. Aerosol mass concentrations increased by 13-18% upon exposure to 15 ppb O and by 8-42% upon exposure to 0.

Gas-Phase Mechanisms of the Reactions of Reduced Organic Nitrogen Compounds with OH Radicals.

Research on the fate of reduced organic nitrogen compounds in the atmosphere has gained momentum since the identification of their crucial role in particle nucleation and the scale up of carbon capture and storage technology which employs amine-based solvents. Reduced organic nitrogen compounds have strikingly different lifetimes against OH radicals, from hours for amines to days for amides to years for isocyanates, highlighting unique functional group reactivity. In this work, we use ab initio methods to investigate the gas-phase mechanisms governing the reactions of amines, amides, isocyanates and carbamates with OH radicals.

Research highlights: laboratory studies of the formation and transformation of atmospheric organic aerosols.

Atmospheric particles are emitted from a variety of anthropogenic and natural precursors and have direct impacts on climate, by scattering solar irradiation and nucleating clouds, and on health, by causing oxidative stress in the lungs when inhaled. They may also form from gaseous precursors, creating complex mixtures of organic and inorganic material. The chemical composition and the physical properties of aerosols will evolve during their one-week lifetime which will consequently change their impact on climate and health.

Experimental and theoretical understanding of the gas phase oxidation of atmospheric amides with OH radicals: kinetics, products, and mechanisms.

Atmospheric amides have primary and secondary sources and are present in ambient air at low pptv levels. To better assess the fate of amides in the atmosphere, the room temperature (298 ± 3 K) rate coefficients of five different amides with OH radicals were determined in a 1 m(3) smog chamber using online proton-transfer-reaction mass spectrometry (PTR-MS). Formamide, the simplest amide, has a rate coefficient of (4.

Gas phase oxidation of monoethanolamine (MEA) with OH radical and ozone: kinetics, products, and particles.

Monoethanolamine (MEA) is currently the benchmark solvent in carbon capture and storage (CCS), a technology aimed at reducing CO2 emissions in large combustion industries. To accurately assess the environmental impact of CCS, a sound understanding of the fate of MEA in the atmosphere is necessary. Relative and absolute rate kinetic experiments were conducted in a smog chamber using online proton transfer reaction mass spectrometry (PTR-MS) to follow the decay of MEA.

Aerobic and electrochemical oxidative cross-dehydrogenative-coupling (CDC) reaction in an imidazolium-based ionic liquid.

The ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [BMIm][BF(4)] has demonstrated high efficiency when applied as a solvent in the oxidative nitro-Mannich carbon--carbon bond formation. The copper-catalyzed cross-dehydrogenative coupling (CDC) between N-phenyltetrahydroisoquinoline and nitromethane in [BMIm][BF(4)] occurred with high yield under the described reaction conditions. Both the ionic liquid and copper catalyst were recycled nine times with almost no lost of activity.

Copper-catalyzed oxidative coupling of benzylic C-H bonds with 1,3-dicarbonyl compounds.

A copper-catalyzed oxidative coupling of benzylic C-H bonds with 1,3-dicarbonyl compounds is described. The reaction utilizes an inexpensive copper catalyst-oxidant system that is suitable for the coupling of a range of benzylic C-H bonds with various 1,3-dicarbonyl compounds. Kinetic isotope studies support a mechanism involving a benzylic hydrogen abstraction.