Polycyclic aromatics nitration

Dewar and his co-workers, as mentioned above, investigated the reactivities of a number of polycyclic aromatic compounds because such compounds could provide data especially suitable for comparison with theoretical predictions ( 7.2.3). This work was extended to include some compounds related to biphenyl. The results were obtained by successively compounding pairs of results from competitive nitrations to obtain a scale of reactivities relative to that of benzene. Because the compounds studied were very reactive, the concentrations of nitric acid used were relatively small, being o-i8 mol 1 in the comparison of benzene with naphthalene, 5 x io mol 1 when naphthalene and anthanthrene were compared, and 3 x io mol 1 in the experiments with diphenylamine and carbazole. The observed partial rate factors are collected in table 5.3. Use of the competitive method in these experiments makes them of little value as sources of information about the mechanisms of the substitutions which occurred this shortcoming is important because in the experiments fuming nitric acid was used, rather than nitric acid free of nitrous acid, and with the most reactive compounds this leads to a... 

TABLE 5.3 The nitration of polycyclic aromatic compounds in solutions of acetyl nitrate in acetic anhydride... 

Reactivity numbers of the most reactive positions have been used to correlate the reactivities in nitration (see below) and other substitutions of a series of polycyclic aromatic hydrocarbons, and they give somewhat better correlations than any of the other commonly used indices of reactivity. The relationship shown below, which was discussed earlier ( 7.1.1),... 

Polycyclic aromatic hydrocarbons (PAH) Apply sample solution and dry. Place TLX2 plate for 20 min in a twin-trough chamber containing phosphorus pentoxide to which 2 to 3 ml cone, nitric acid have been added. PAH nitrated by nitrous fumes. [20]... 

One example of normal-phase liquid chromatography coupled to gas chromatography is the determination of alkylated, oxygenated and nitrated polycyclic aromatic compounds (PACs) in urban air particulate extracts (97). Since such extracts are very complex, LC-GC is the best possible separation technique. A quartz microfibre filter retains the particulate material and supercritical fluid extraction (SPE) with CO2 and a toluene modifier extracts the organic components from the dust particles. The final extract is then dissolved in -hexane and analysed by NPLC. The transfer at 100 p.1 min of different fractions to the GC system by an on-column interface enabled many PACs to be detected by an ion-trap detector. A flame ionization detector (PID) and a 350 p.1 loop interface was used to quantify the identified compounds. The experimental conditions employed are shown in Table 13.2. 

Alkylated, oxygenated and nitrated polycyclic aromatic compounds... 

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

For soybean-based biodiesel at this concentration, the estimated emission impacts for percent change in emissions of NO,, particular matter (PM), HC, and CO were +20%, -10.1%, -21.1%, and -11.0%, respectively (EPA, 2002). The use of blends of biodiesel and diesel oil are preferred in engines in order to avoid some problems related to the decrease of power and torque, and to the increase of NO, emissions (a contributing factor in the localized formation of smog and ozone) that occurs with an increase in the content of pure biodiesel in a blend. Emissions of all pollutants except NO appear to decrease when biodiesel is used. The use of biodiesel in a conventional diesel engine dramatically reduces the emissions of unbumed hydrocarbons, carbon dioxide, carbon monoxide, sulfates, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatic hydrocarbons, ozone-forming hydrocarbons, and particulate matter. The net contribution of carbon dioxide from biomass combustion is small. 

Ramdahl, T., Becher, G., and Bjorseth, A. Nitrated polycyclic aromatic hydrocarbons in urban air particles. Environ. Sci. Technol, 16(12) 861-865, 1982. 

Eriksson, M. Sodersten, E. Yu, Z. DaUiammar, G. Mohn, W.W. Degradation of polycyclic aromatic hydrocarbons at low temperature under aerobic and nitrate-reducing conditions in enrichment cultures from northern soils. Appl. Environ. Microbiol. 2003, 69, 275-284. 

Maximum residue levels in certain foods are set for the following contaminants nitrate, my cotoxins (aflatoxins, ochratoxin A, pamlin, deoxynivalenol, zearalenone, fumonisins, T -2 and HT-2-toxin), metals (lead, cadmium, mercury, inorganic tin), 3-MCPD (3-monochloro-propane-l,2-diol), dioxins and PCBs, and polycyclic aromatic hydrocarbons (benzo(a)pyrene) (EC 2007c). 

C. L. Crespi, Human Cell Mutagenicity of Oxygenated, Nitrated, and Unsubstituted Polycyclic Aromatic Hydrocarbons Associated with Urban Aerosols, Mutat. Res., 371, 123-157 (1996). 

Nielsen, T., Reactivity of Polycyclic Aromatic Hydrocarbons towards Nitrating Species, Environ. Sci, Technol., 18, 157-163 (1984). 

Pitts, J. N Jr., Nitration of Gaseous Polycyclic Aromatic Hydrocarbons in Simulated and Ambient Urban Atmospheres A Source of Mutagenic Nitroarenes, Atmos. Environ., 21, 2531-2547 (1987). 

Ramdahl, T., A. Bjprseth, D. Lokensgard, and J. N. Pitts, Jr., Nitration of Polycyclic Aromatic Hydrocarbons Adsorbed to Different Carriers in a Fluidized Bed Reactor, Chemosphere, 13, 527-534 (1984b). 

Robbat, A., Jr., N. P. Corso, P. J. Doherty, and M. H. Wolf, Gas Chromatographic Chemiluminescent Detection and Evaluation of Predictive Models for Identifying Nitrated Polycyclic Aromatic Hydrocarbons in a Diesel Fuel Particulate Extract, Anal. Chem., 58, 2078-2084 (1986). 

Rosenkranz, H. S., and R. Mermelstein, The Genotoxicity, Metabolism, and Carcinogenicity of Nitrated Polycyclic Aromatic Hydrocarbons, J. Environ. Sci. Health, C3, 221-272 (1985a). 

Ruehle, P. H., L. C. Bosch, and W. P. Duncan, Synthesis of Nitrated Polycyclic Aromatic Hydrocarbons, in Nitrated Polycyclic Aromatic Hydrocarbons (C. M. White, Ed.), pp. 169-235, Hiithig, Heidelberg, 1985. 

Schuetzle, D., T. L. Riley, T. J. Prater, T. M. Harvey, and D. F. Hunt, Analysis of Nitrated Polycyclic Aromatic Hydrocarbons in Diesel Particulate, Anal. Chem., 54, 265-271 (1982). 

White, C. M., Ed., Nitrated Polycyclic Aromatic Hydrocarbons, Hiithig, Heidelberg, 1985. 

Wilson, N. K., T. R. McCurdy, and J. C. Chuang, Concentrations and Phase Distributions of Nitrated and Oxygenated Polycyclic Aromatic Hydrocarbons in Ambient Air, Atmos. Environ., 29, 2575-2584 (1995). 

Bezabeh, D. Z., T. M. Allen, E. M. McCauley, P. B. Kelly, and A. D. Jones, Negative Ion Laser Desorption Ionization Time-of-Flight Mass Spectrometry of Nitrated Polycyclic Aromatic Hydrocarbons, J. Am.. Soc. Mass Spectrom., 8, 630-636 (1997). 

White, Nitrated Polycyclic Aromatic Hydrocarbons, Huthig, Heidelberg 1984. 

Thermochemical data are available (Ref 2) on the heats of combustion and formation for all five isomers, on the heats of nitration from various Dinitrotoluenes for the 23,4-, 2,4,5-, and 2,3,6-isomers, and on the heats of crystn for the 2,3,4- and 2,4,5-isomers. Data are also available (Ref 1) on the shock sensitivities of all of the isomers except 2,3,6-, and on the rates of decompn at 140° of the 23,4-, 2,4,5-, and 23,5-isomers. The detonation pressure and the temp coefficient of decompn between 140 and 180° have been measured for the 2,4,5-isomer 2,3,4- and 2,4,5-TNT form addition compds ( 7r-complexes ) at 1 1 molar ratio with several polycyclic aromatic hydrocarbons (naphthalene, acenaphthene, fluorene, phenanthrene and anthracene) (Ref 2). 2,4,5-TNT forms complexes with 4-aminozaobenzene, 4-aminoacetophenone, bis (2 hydroxy ethyl) amine, and tris (2-hydroxy-ethyl) amine (Ref 1). The first two have a 1 1 molar ratio, the third 1 2, and the fourth 2 1. Upon heating, the two 4-amino compds react with replacement of the 5-nitro group, as discussed below... 

Many polycyclic aromatic amines and aldehydes are commercially available, but their supply is very limited. Preparation of these starting materials is necessary for studying the (3-lactam formation reaction [93]. Nitro compounds are the precursors for the amines. An important task was to prepare polycyclic aromatic nitro compounds, particularly those of chrysene, phenanthrene, pyrene, and dibenzofluorene in good yield. Nitration of these hydrocarbons with concentrated nitric acid in sulfuric acid is a widely used reaction for this purpose. Our research culminated in facile synthesis of polyaromatic nitro derivative 9 starting from polyaromatic hydrocarbons (PAHs) 8 through the use of bismuth nitrate impregnated with clay (Scheme 1) ([94, 95] for some examples of bismuth nitrate-catalyzed reactions... 

A. C. Lewis, R. E. Robinson, K. D. Bartle and M. J. Pilling, On-line coupled LC-GC-ITD/MS for the identification of alkylated, oxygenated and nitrated polycyclic aromatic compounds in urban air particulate extracts , Environ. Sci. Technol. 29 1977-1981 (1995). 

Wilson, N.K., T.R. McCurdy, and J.C. Chuang. 1995. Concentrations and phase distributions of nitrated and oxygenated polycyclic aromatic hydrocarbons in ambient air. Atmos. Environ. 29 2575-2584. 

Organic gases Hydrocarbons Aldehydes, ketones Other organics Benzene, butadiene, butene, ethylene, isooctane, methane Acetone, formaldehyde Acids, alcohols, chlorinated hydrocarbons, peroxyacyl nitrates, polynuclear aromatics There are two main groups of hydrocarbons of concern volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). 

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