Under optimal conditions the reactions exhibit high para selectivity with little or no adamantane sideproduct being formed
The synthetic scope of this transformation was tested for representative alkylbenzenes and haloalkylbenzenes. 6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid in Medicinal Chemistry carried out in 1,2-dichloroethane (DCE) produce increased amounts of the meta isomer and substantial amounts of adamantane. Substrate selectivities (K(T)/K(B)) were measured in competitive experiments in [BMIM][OTf] and in DCE as solvents. Isomerization tests were performed to shed light on the origin of the meta isomer. A DFT study was also conducted to compare relative stabilities of the isomeric products, to gauge the relative stabilities of the intermediate isomeric benzenium ions of adamantylation and their charge distribution modes, and to explore the intramolecular process for isomerization in the benzenium Enhanced degradation of chlorinated ethylenes in groundwater from a paint contaminated site by two-stage fluidized-bed reactor.of Science and Technology, Daejeon 305-701, South Korea.
Groundwater, used in this study, contaminated predominantly with aromatic compounds, was biologically treated in a fluidized-bed reactor (FBR) with immobilized cells. The aromatics were completely decomposed, while cis-1,2-dichloroethylene (cis-DCE) and trichloroethylene (TCE) were decomposed only approximately 20% and 5%, respectively. In these studies a significant improvement of the decomposition efficiency for chlorinated ethylenes was achieved by utilizing cometabolism. Methanol (MeOH) and toluene were used as the substrate in the case of one-stage reactor (Single Reactor). MeOH (187 mg l(-1)) increased the decomposition efficiency up to 40% and 60% for cis-DCE and TCE, respectively, while toluene (20 mg l(-1)) increased the decomposition efficiency of cis-DCE to 92% and the decomposition efficiency of TCE to 76%. In the case of two-stage reactor system (Reactor 1 and Reactor 2), MeOH and methane (CH4) were used as the substrate. In this system, cells grown on MeOH or CH4 in the Reactor 1 were continuously fed into Reactor 2 and groundwater was fed into Reactor 2 only.
When MeOH (384 mg l(-1) d(-1)) was used as substrate the decomposition efficiency of cis-DCE and TCE were 60% and 70%, respectively. Similar decomposition efficiency was observed for a small amount of CH4 (19 mg l(-1) Measurement of emissions from air pollution sources. 3. C1-C29 organic compounds Organic compound emission rates for volatile organic compounds (VOC), gas-phase semivolatile organic compounds, and particle-phase organic compounds are measured from residential fireplace combustion of wood. Firewood from a conifer tree (pine) and from two deciduous trees (oak and eucalyptus) is burned to determine organic compound emissions profiles for each wood type including the distribution of the alkanes, alkenes, aromatics, polycyclic aromatic hydrocarbons (PAH), phenol and substituted phenols, guaiacol and substituted guaiacol, syringol and substituted syringols, carbonyls, alkanoic acids, resin acids, and levoglucosan. Levoglucosan is the major constituent in the fine particulate emissions from all three wood types, contributing 18-30% of the fine particulate organic compound emissions. Guaiacol (2-methoxyphenol), and guaiacols with additional substituents at position 4 on the molecule, and resin acids are emitted in significant quantities from pine wood combustion.
Syringol (2,6-dimethoxyphenol) and syringols with additional substituents at position 4 on the molecule are emitted in large amounts from oak and eucalyptus firewood combustion, but these compounds are not detected in the emissions from pine wood combustion. Syringol and most of the substituted syringols are found to be semivolatile compounds that are present in both the gas and particle phases, but two substituted syringols that have not been previously quantified in wood smoke emissions, propionylsyringol and butyrylsyringol, are found exclusively in the particle phase and can be used to help trace hardwood smoke particles in the atmosphere. Benzene, ethene, and acetylene are often used as tracers for motor vehicle exhaust in the urban atmosphere. The contribution of wood smoke to the ambient concentrations of benzene, ethene, and acetylene could lead to an overestimate of the contribution of motor vehicle tailpipe exhaust to Neutrotropic effects and blood levels of solvents at combined exposures: binary mixtures of toluene, o-xylene and acetone in rats and mice.Male rats and female mice were exposed to vapours of toluene, o-xylene and acetone in basic or double concentrations or to binary combinations of basic concentrations, for 4 and 2 hours, respectively. Basic air concentrations were for rats and mice (in ppm): toluene 270 and 380, o-xylene 230 and 320, acetone 1700 and 1530, respectively. The CNS effect-inhibition of electrically evoked seizure discharge-was measured immediately after exposure and blood levels of solvents were monitored during the desaturation phase.
The effect of all binary mixtures was lower than that of double concentrations of each single component, the difference being significant only in mice, and lower than the additive effects predicted on the basis of regressions of the effect on air or on blood concentrations of individual components.
