Naphthalene benzene

The purpose of this eornpuLer project is Lo examine several polynuclear aromatic hydrocarbons and to relate their electron density patterns to their carcinogenic activity. If nucleophilic binding to DN.A is a significant step in blocking the normal transcription process of DN.A, electron density in the hydrocarbon should be positively correlated to its carcinogenic potency. To begin with, we shall rely on clinical evidence that benzene, naphthalene, and phenanthrene... 

In addition to benzene and naphthalene derivatives, heteroaromatic compounds such as ferrocene[232, furan, thiophene, selenophene[233,234], and cyclobutadiene iron carbonyl complexpSS] react with alkenes to give vinyl heterocydes. The ease of the reaction of styrene with sub.stituted benzenes to give stilbene derivatives 260 increases in the order benzene < naphthalene < ferrocene < furan. The effect of substituents in this reaction is similar to that in the electrophilic aromatic substitution reactions[236]. 

In general the most stable resonance structure for a polycyclic aromatic hydro carbon is the one with the greatest number of rings that correspond to Kekule formula tions of benzene Naphthalene provides a fairly typical example... 

CNDO calculations provide estimates of the localization energies. For benzene, naphthalene, and anthracene, these are, respectively, 36.3, 15.4, and 8.3 kcal/mol. ... 

The effective use of column volume overload for preparative separations was experimentally demonstrated by Scott and Kucera [1]. These authors used a column 25 cm long, 4.6 mm I.D. packed with Partisil silica gel 10 mm particle diameter and employed n-heptane as the mobile phase. The total mass of sample injected was kept constant at 176 mg, 8 mg and 0.3 mg of benzene, naphthalene and anthracene, respectively, but the sample volumes used which contained the same mixture of solutes were 1 pi, 1 ml, 2 ml and 3 ml. The chromatograms of each separation are... 

Figure 4. Graphs of the Retention Distance of the Peaks of Benzene, Naphthalene and Anthracene against Sample Volume...

At this stage the benzene is still just separated from the naphthalene. A 16 ml sample volume demonstrates the complete frontal analysis chromatogram of the mixture. The first and second steps containing pure benzene and benzene + naphthalene, respectively, the center peak containing all three solutes and the last two steps containing naphthalene plus anthracene and pure anthracene, respectively. 

There are many examples in the literature of the exchange of aromatic hydrogens in benzene, naphthalene and tetralin derivatives which employ... 

The quantum-mechanical treatment previously applied to benzene, naphthalene, and the hydrocarbon free radicals is used in the calculation of extra resonance energy of conjugation in systems of double bonds, the dihydro-naphthalenes and dihydroanthracenes, phenylethylene, stilbene, isostilbene, triphenylethylene, tetraphenylethyl-... 

It is, however, reasonable to assume that, in the case of closely similar reactions, that reaction leading to the most stable product will occur most easily. This hypothesis leads to a complete explanation of the observed courses of hydrogenation of benzene, naphthalene, and anthracene, which are represented by the following schemes, showing only the reactions for which data are available.5... 

The reaction has been applied to nonheterocyclic aromatic compounds Benzene, naphthalene, and phenanthrene have been alkylated with alkyllithium reagents, though the usual reaction with these reagents is 12-20, and Grignard reagents have been used to alkylate naphthalene. The addition-elimination mechanism apparently applies in these cases too. A protected form of benzaldehyde (protected as the benzyl imine) has been similarly alkylated at the ortho position with butyl-lithium. ... 

A strain of Rhodococcus sp. was capable of degrading a number of chlorinated aliphatic hydrocarbons including vinyl chloride and trichloroethene, as well as the aromatic hydrocarbons benzene, naphthalene, and biphenyl (Malachowsky et al. 1994). 

Experiments using marine sediment slurries have examined the effect of pre-exposure to various aromatic hydrocarbons on the rate of subsequent degradation of the same, or other hydrocarbons. The results clearly illustrated the complexity of the selection process for example, whereas pre-exposure to benzene, naphthalene, anthracene, or phenanthrene... 

Allen CCR, DR Boyd, H Dalton, ND Sharma, I Brannigan, NA Kerley, GN Sheldrake, SC Taylor (1995) Enantioselective bacterial biotransformation routes to cw-diol metabolites of monosubstituted benzenes, naphthalene and benzocycloalkenes of either absolute configuration. J Chem Soc Chem Commun 117-118. 

The type of treatment applied significantly affected the benzene/naphthalene (B/N) product ratio (Fig. 6). Thus, treatment with oxalic and citric acids, steaming plus HC1 washing, and partial Cs-exchanged increased the B/N ratio with respect to the untreated sample. In the first three cases, this effect may be explained by a preferential removal of the acid sites at the external zeolite surface, where naphthalene is predominantly formed [6], The reason of the increased B/N ratio in the 3Mo/CsHZ5 sample still needs to be elucidated, but a decrease in surface acidity in combination with an enhanced shape selectivity effect due to presence of voluminous Cs+ cations inside the micropores (a decrease in Vmicrop was noticed in Table 1) may be hypothesized. 

Type 61b of the intensely colored quinocyclopropenes is represented by the di-cyanomethylene species 115 and 118 of p- and o-quinonoid structure. In addition to the systems 115,119, and 122 reported by Gompper1001 a series of o- and p-quino-cyclopropenes in the benzene, naphthalene, anthracene, phenanthrene, and fluorene series (718-125) were prepared75) carrying the bis-(p-anisyl)-cyclopropenyl residue, which brings about a better stabilization of the cyclopropenium moiety101 ... 

Photochemical osmylation. The irradiation of the charge-transfer bands (Fig. 13) of the EDA complex of 0s04 with various benzenes, naphthalenes, anthracenes, and phenanthrene yields the same osmylated adducts as obtained in the thermal reactions. For example, irradiation of the purple solution of anthracene and 0s04 in dichloromethane at k > 480 nm yields the same 2 1 adduct (B) together with its syn isomer as the sole products, i.e.,... 

B. Tetranitromethane. Tetranitromethane forms colored charge-transfer (CT) complexes with a variety of organic donors such as substituted benzenes, naphthalenes, anthracenes, enol silyl ethers, olefins, etc. For example, an orange solution is instantaneously obtained upon exposure of a colorless solution of methoxytoluene (MT) to tetranitromethane (TNM),237 i.e.,... 

Schwarz, F.P., Wasik, S.P. (1976) Fluorescence measurements of benzene, naphthalene, anthracene, pyrene, fluoranthene, and benzo[a]pyrene in water. Anal. Chem. 48, 524—528. 

Molecular structure can have a profound effect on the position in the spectrum where fluorescence occurs, as well as on its intensity. It can be shown by quantum mechanics that the more extended a conjugated system is, the smaller will be the separation in energy between the ground state and the lowest excited singlet state. This is evident in the fact that benzene, naphthalene, and anthracene, having one, two, and three rings, fluoresce maximally at 262 nm, 320 nm, and 379 nm, respectively. 

Borowski and coworkers have reported that benzene, naphthalene, and anthracene are reduced to cyclohexane, tetralin and a mixture of 1,2,3,4-tetrahy-droanthracene (4H-An) and 1,2,3,4,5,6,7,8-octahydroanthracene (8H-An), respectively, in the presence of the dihydride bishydrogen complex RuH2(H2)2(PCy3)2 (80 °C, 3-30 bar H2) [18], Notably, the latter was found to react at 80°C with neat benzene or with cyclohexane solutions of naphthalene or tetralin to form the corresponding // -adducts (Scheme 16.4). These products were also isolated from the final catalytic mixtures. 

Group contribution method of Andersen, Beyer, and Watson [51,52] In this method, a given compound is constructed from abase group (methane, cyclopentane, benzene, naphthalene, methylamine, dimethylamine, trimethylamine, or formamide) with known enthalpies of formation, which is then modified by appropriate substitutions to yield the desired molecule. 

As described above, when CuCl is regenerated in the reaction, the process can be catalytic in copper. In other cases, a stoichiometric amount (2 equiv.) of CuCl is used. Although CuCN shows similar reactivity, CuBr and Cul are not so effective as compared to CuCl. Allylation benzene, naphthalene, and anthracene formation, as well as acylation are representative examples, which are described below. 

Broadly speaking, the cavity sizes of a-, f -, and y-CD are appropriate for binding simple derivatives of benzene, naphthalene, and anthracene, respectively (Sanemasa and Akamine, 1987 Fujiki et al., 1988 Sanemasa et al., 1989). Many studies of the inclusion of aromatics, particularly of dyes and other molecules with strong chromophores, have been reported, and these have been useful in delineating the main features of CD binding (Bender and Komiyama, 1978 Saenger, 1980 Szejtli, 1982 Atwood et al., 1984 Stoddart and Zarzycki, 1988). In contrast, the affinity of small to medium aliphatic molecules for CDs have been less well studied, most... 

More easily than benzene, naphthalene can be oxidised directly to (a)-quinone this is the preparative method with anthracene and phenan-threne. 

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