Aromatic hydrocarbons study

Plots of 8/ / versus the quantity in parentheses were linear for all eleven aromatic hydrocarbons studied and the slope yielded values ranging from 0.32 to 0.85. Since the sum of 0/ and (° was unity, the important conclu-... 

Norden, B., Edlund, U., and Wold, S., Carcinogenicity of polycyclic aromatic hydrocarbons, studied by SIMCA pattern recognition, Acta Chemica Scandinavica Series B, 32, 602-608, 1978. 

Bandow H, WashidaN, Akimoto H. 1985. Ring-cleavage reactions of aromatic hydrocarbons studied by FT-IR spectroscopy I. Photooxidation of toluene and benzene in the NOx-Air System. Bull Chem Soc Jpn 58 2531-2540. 

Polycyclic Aromatic Hydrocarbon Study (51). The data were taken from papers by Dipple (52) and McCann t al. (53). In the Dipple data set, several hundred polycyclic aromatic hydrocarbons are arranged according to their carcinogenic potency into four classes inactive, slight, moderate, and high. These... 

Bandow, H. and N. Washida Ring-Cleavage Reactions of Aromatic-Hydrocarbons Studied by Ft-Ir Spectroscopy. 2. Photooxidation of Ortho-Xylenes, Meta-Xylenes, and Para-Xylenes in the Nox-Air System, Bulletin of the Chemical Society of Japan, 58 (1985a) 2541-2548. 

Aqueous solubility data for the 12 aromatic hydrocarbons studied in this investigation are reported in this section. The solubilities determined spanned a range of 106. The solubilities measured at 25°C are compared with values reported by other investigators and are correlated with molecular parameters such as carbon number, molar volume, and molecular length. 

A-4. Preparation of Standard Solutions. Standard solutions of the aromatic hydrocarbons studied in this investigation were prepared by the direct method. Solutes were weighed on a Cach Electrobalance, dissolved in acetonitrile, and made up to a 500-mL volume in a class A volumetric flask. 

Figure 27. The structures of co/o-condensed polycyclic aromatic hydrocarbons studied 1, naphthalene 2, anthracene 3, phenanthrene 4, triphenylene 5, chrysene 6, benzanthracene 7, dibenz(o,c)anthracene 8, dibenz(u,/i)-anthracene 9, benzo(h)chrysene.

Figure 28. The structures of peri-condensed polycyclic aromatic hydrocarbons studied 10, pyrene 11, benzo((f)pyrene 12, perylene 13, benzo(a)pyrene 14, benzo(c,d,e)pyrene 15, anthranthrene 16, coronene.

Dinadayalane, T. C., Sastry, G. N. (2002a). Structure-energy relationships in curved polycyclic aromatic hydrocarbons Study of benzo-corannulenes. Journal of Organic Chemistry, 67,... 

For hydrocarbon studies, analyses can be made without prior assumptions, since the carbons not carrying protons can be excited directly, this of course not being the case for hydrogen (e.g., quaternary carbons in alkanes, substituted carbons in aromatic rings). 

More information has appeared concerning the nature of the side reactions, such as acetoxylation, which occur when certain methylated aromatic hydrocarbons are treated with mixtures prepared from nitric acid and acetic anhydride. Blackstock, Fischer, Richards, Vaughan and Wright have provided excellent evidence in support of a suggested ( 5.3.5) addition-elimination route towards 3,4-dimethylphenyl acetate in the reaction of o-xylene. Two intermediates were isolated, both of which gave rise to 3,4-dimethylphenyl acetate in aqueous acidic media and when subjected to vapour phase chromatography. One was positively identified, by ultraviolet, infra-red, n.m.r., and mass spectrometric studies, as the compound (l). The other was less stable and less well identified, but could be (ll). 

Hydrocarbons are divided into two mam classes aliphatic and aromatic This classifi cation dates from the nineteenth century when organic chemistry was devoted almost entirely to the study of materials from natural sources and terms were coined that reflected a substance s origin Two sources were fats and oils and the word aliphatic was derived from the Greek word aleiphar meaning ( fat ) Aromatic hydrocarbons irre spective of their own odor were typically obtained by chemical treatment of pleasant smelling plant extracts... 

Difluoronaphthalene [315-52-6] is prepared from 4-fluoro-l-naphthylarnine by the Balz-Schiemann reaction. 1,4-Difluoronaphthalene is used in chemical carcinogenesis studies as a synthon for highly condensed difluoro—polycycHc aromatic hydrocarbons (273). 

A wide variety of guest molecules may be trapped by the Wemer-type crystalline host lattice, ranging, eg, from noble gases to condensed aromatic hydrocarbons. These clathrates may be formed from solution or by sorption. Kinetics of sorption—desorption have been studied (83). 

Decomposition late studies on dialkyl peioxydicaibonates ia vaiious solvents leveal diamatic solvent effects that ptimatily lesult fiom the susceptibiUty of peioxydicaibonates to iaduced decompositions. These studies show a decieasiag oidei of stabiUty of peioxydicaibonates ia solvents as follows TCE > saturated hydrocarbons > aromatic hydrocarbons > ketones (29). Decomposition rates are lowest in TCE where radicals are scavenged before they can induce the decomposition of peroxydicarbonate molecules. 

The fused 3+ ring aromatics in petroleum include both cata- and peri-condensed stmctures (see Table 4, Fig. 8). The cata-condensed species are those stmctures where only one face is shared between rings, the peri-condensed molecules are those that share more than one face. The fused ring aromatics form the class of compounds known as polynuclear aromatic hydrocarbons (PAH) which includes a number of recognized carcinogens in the 4+ ring family (33). Because of the potential health and environmental impact of PAH, these compounds have been studied extensively in petroleum. 

Several solvent uses have been proposed. Dimethyl sulfate has been used as a solvent for the study of Lewis acid—aromatic hydrocarbon complexes (148). It also is effective as an extraction solvent to separate phosphoms haUde—hydrocarbon mixtures and aromatic hydrocarbons from aUphatics, and it acts as an electrolyte in electroplating iron (149—152). The toxicity of dimethyl sulfate precludes its use as a general-purpose solvent. 

Benzene monoxide-oxepin and its sulfur analog are treated elsewhere (Chapter 5.1.7) (67AG(E)385). However, we point out here that electron-withdrawing substituents often favor the benzene oxide tautomer. The first study on oxides of the environmentally hazardous polychloro- and polybromo-biphenyls shows that they exist mainly in the benzene oxide form (81JOC3721). Oxides of polynuclear aromatic hydrocarbons (PAH) also exist mainly in the fused-ring oxirane form. 

BP Chemicals studied the use of chloroaluminates as acidic catalysts and solvents for aromatic hydrocarbon allcylation [41]. At present, the existing AICI3 technology (based on red oil catalyst) is still used industrially, but continues to suffer from poor catalyst separation and recycling [42]. The aim of the work was to evaluate the AlCl3-based ionic liquids, with the emphasis placed on the development of a clean... 

That the reaction with a lower rate constant is taking place preferentially and that the rate increases during the reaction are phenomena that can also occur with parallel reactions. As an example, Wauquier and Jungers (48), when studying competitive hydrogenation of a series of couples of aromatic hydrocarbons on Raney-nickel, have observed these phenomena for the couple tetraline-p-xylene (Table I). The experimental result was... 

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