A series of acyl peroxy radical H-shifts were systematically studied using computational approaches. The radicals categorized into small- (ethanal - pentanal), medium- (hexanal and heptanal) large-sized...

Photochemical oxidation of aromatic hydrocarbons leads to tropospheric ozone and secondary organic aerosol (SOA) formation, with profound implications for air quality, human health, and climate. Toluene is the most abundant aromatic compound under urban environments, but its detailed chemical oxidation mechanism remains uncertain. From combined laboratory experiments and quantum chemical calcul...

The OH oxidation of α-pinene under both lowand high-NOx environments was studied in the Caltech atmospheric chambers. Ozone was kept low to ensure OH was the oxidant. The initial α-pinene concentration was 20–50 ppb to ensure that the dominant peroxy radical pathway under low-NOx conditions is reaction with HO2, produced from reaction of OH with H2O2, and under high-NOx conditions, reactions wi...

Cavity ringdown spectra (CRDS) of the near IR Ã2A′ X̃2A′′ electronic transition of phenyl peroxy radical are reported. The electronic origin is observed at 7497 cm−1. Ab initio calculations have been carried out to aid the assignement of the electronic origin and other bands involving vibrational excitation.

The Tropospheric ORganic CHemistry experiment (TORCH) took place during the heatwave of summer 2003 at Writtle College, a site 2 miles west of Chelmsford in Essex and 25 miles north east of London. The experiment was one of the most highly instrumented to date. A combination of a large number of days of simultaneous, collocated measurements, a consequent wealth of model constraints and a highly...

1. Oxygen radicals in biological systems and the importance of iron Oxygen radicals can be either organic or inorganic. The organic radicals such as the peroxy (ROO') and alkoxy (RO') are those derived from complex molecules like the polyunsaturated fatty acids. The inorganic oxygen radicals are the superoxide radical (O,-*) and the hydroxyl radical (OH'). Formation of the highly reactive hydro...

Using quantum mechanical calculations, we have investigated hydrogen shift (H-shift) reactions in peroxy radicals derived from the atmospheric oxidation of 1-pentene (CH2═CHCH2CH2CH3) and its monosubstituted derivatives. We investigate the peroxy radicals, HOCH2CH(OO)CR1HCH2CH3, HOCH2CH(OO)CH2CR1HCH3, and HOCH2CH(OO)CH2CH2CR1H2, where the substituent R1 is an alcoholic (OH), a hydroperoxy (OOH)...

To clarify whether polyamines scavenge alkyl (carbon-centered) and peroxy (oxygen-centered) radicals, we analyzed their effects on the kinetics of polymerization of methyl methacrylate (MMA) induced by 2,2'-azobisisobutyronitrile (AIBN, a R* radical) and benzoyl peroxide (BPO, a PhCOO* radical) under nearly anaerobic conditions. Stoichiometric factors (n; number of free radicals trapped by one ...