Hydrocarbons anthracene

Bauer, J.E. and O.G. Capone. 1985. Degradation and mineralization of the polycyclic aromatic hydrocarbons anthracene and naphthalene in intertidal marine sediments. Appl. Environ. Microbiol. 50 81-90. 

Figure 4. Calculation of the substrate uptake driven diffusive transfer of the polycyclic aromatic hydrocarbon anthracene to Mycobacterium sp. LB501T (solid line) and three other imaginary bacterial strains differing from strain LB501T by their 100-fold lower (dots), 10-fold lower (long dashes) and 10-fold higher (short dashes) specific affinities,...

Aromatic Hydrocarbons. Anthracene (henceforth abbreviated "A"), phenanthrene (Ph), pyrene (Py), benzo[a]pyrene (BaP), and benz[a]-anthracene (BaA) were obtained from commercial sources and, when required, were purified by vacuum sublimation. 

Shortly thereafter, an inexpensive procedure for the industrial production of 1 from readily available starting materials was elaborated (Bayer, 1878)." In related efforts, chemists identified another compound, alizarine 3, which was isolated from a certain species of plants Rubia tinctoria). It was used for centuries as a natural dye. Originally very expensive, it soon became an inexpensive product owing to the ease of its synthesis from the aromatic hydrocarbon anthracene, present in coal tar (Grebe and Lieberman, 1868). ... 

Reduction of aromatic hydrocarbons. Anthracene is reduced quantitatively to 9,10-dihydroanthraccncby sodium in HMPT with THF as cosolvent. The reaction has been extended to benzanthracene, tetracene, and 9-alkyl- and 9,10-dialkylanthraocnes to give the corresponding mejo-dihydro derivatives. Water or methanol diluted in THF is used as the proton source. ... 

Perkey and Farhataziz [38] have measured the rate constants for the reaction of e am with some aromatic hydrocarbons (anthracene, nitrobenzene, phenan-threne, naphthalene, benzamide), with acetone and with dichloromethane, 1,2-dichloroethane, and 1-chloropropane. In the case of the aromatic molecules listed above, the rate constants are an order of magnitude larger than the corresponding values in water, reflecting the lower viscosity of liquid ammonia and indicating that the reactions are diffusion-controlled. In the case of biphenyl (B), the reaction of e am was found to be reversible [39] ... 

Figure 4.13 is a plot of the experimental data for a series of methylbenzenes with n = 1 to 6 with the aromatic hydrocarbons anthracene, A pyrene, Py phenan-threne, P chrysene, C and triphenylene, T versus 0.1/(IP — Ea — C2) with the least-squares value of C2 = 2.90 0.10 eV. If we consider the narrow range of values for these complexes, the correlation is quite good. 

Naphthalene, anthracene, and phenanthrene are the three simplest members of this class. They are all present in coal tar, a mixture of organic substances formed when coal is converted to coke by heating at high temperatures (about 1000°C) in the absence of air. Naphthalene is bicyclic (has two rings), and its two benzene rings share a common side. Anthracene and phenanthrene are both tricyclic aromatic hydrocarbons. Anthracene... 

Coal tars are by-products of the carbonization of coal to produce coke and/or natural gas. Physically, they are usually viscous liquids or semi-solids that are black or dark brown with a naphthalene-like odor. The coal tars are complex combinations of polycyclic aromatic hydrocarbons, phenols, heterocyclic oxygen, sulfur, and nitrogen compounds. By comparison, coal tar creosotes are distillation products of coal tar. They have an oily liquid consistency and range in color from yellowish-dark green to brown. The coal tar creosotes consist of aromatic hydrocarbons, anthracene, naphthalene, and phenanthrene derivatives. At least 75% of the coal tar creosote mixture is polycyclic aromatic hydrocarbons (PAHs). Unlike the coal tars and coal tar creosotes, coal tar pitch is a residue produced during the distillation of coal tar. The pitch is a shiny, dark brown to black residue which contains polycyclic aromatic hydrocarbons and their methyl and polymethyl derivatives, as well as heteronuclear compounds... 

Monig and Kriegel [431—436], Siewert [573] and Fox and Price [231] found that the addition of cyclic hydrocarbons (anthracene, pyrene, 3,4-benzpyrene) to solutions of polymethylmethacrylate initiates the sensitized photo-oxidation of the polymer. 

A real advantage of working in the FIR is that both polar and non-polar chains may be searched for. Indeed, the lowest bending frequency of C3 has been studied in the laboratory [69], and tentatively detected toward the galactic centre source Sgr B2 [70]. Other large molecules such as polycyclic aromatic hydrocarbons (anthracene, pyrene, perylene, etc) or biomolecules such as glycine or uracil also possess low-frequency FIR vibrations, and can be produced in sizable quantities in supersonic expansions through heated planar nozzles... 

The theory of luminescence transitions is best described by using a molecular-energy interpretation for a molecular-orbital interpretation, the reader is referred to specialized monographs [1,2]. The transitions of an aromatic hydrocarbon, anthracene, will be used to illustrate the molecular-energy interpretation given below. 

As an example of the first technique, consider the determination of the aromatic hydrocarbon, anthracene, in the presence of its isomer, phenanthrene. Phenan-threne does not absorb in the ultraviolet at wavelengths longer than 360 nm. Since anthracene has an excitation band above 360 nm, it is possible to excite only anthracene. In an experimental study [24] of this type of mixture, the actual wavelength used was 365 nm. As can be seen from Figure 9.8, the best wavelength at which to measure the fluorescence of anthracene on an uncorrected spectrofluorometer would be about 400 nm. It is also possible to determine phenanthrene by use of the second technique. Phenanthrene and anthracene are excited intensely at 265 nm, but phenanthrene fluoresces at 350 nm where anthracene does not (Fig. 9.8). 

The spiroisoxazoline 18, obtained from the nitrone 17 and dicyanoacetylene, rearranges to the pyiTolidinone 19 below 0 °C <97LA1691>. Irradiation of solvent-free mixtures of polycyclic aromatic hydrocarbons (anthracene, phenanthrene and pyrene) and the nitrile oxides mesitonitrile oxide or 3,5-dichloro-2,4,6-trimethylbenzonitrile oxide in a microwave oven at 650 W for 3.5-10 min. yields isoxazolines, e.t . 20, from phenanthrene <97H(45)1567>. 

The molecule of 15,23 16,22-dimethenobenzo[l,2-iZ 4,5-fl ]dipentha-phene (C48H24, Figure 2), also known as kekulene or superbenzene, was studied at both the HF/STO-3G and HF/6-31G levels. The optimized geometry was found to be planar and have D f, symmetry, with the six inner hydrogen atoms separated by only 1.851 A. In addition, structures of five other ben-zenoid hydrocarbons (anthracene, phenanthrene, tetracene, benzanthracene, and chrysene) were optimized. The corresponding total energies were found to... 

The sextet formula for tetracene, for pentacene and for hexacene are respectively depicted in Fig.7 these structures correspond to the properties of the hydrocarbons. Anthracene is colourless but rather reactive and easily adds maleic anhydride tetracene is orange yellow and more reactive pentacene is violet and so reactive that it must be prepared under CO. ... 

Coal tar creosote consists of aromatic hydrocarbons, anthracene, naphthalene, andphenanthrene derivatives. At least 75% of the coal tar creosote mixture is polycyclic aromatic hydrocarbons (PAHs). Unlike the coal tars and coal tar creosotes, coal tar pitch is a residue produced during the distillation of coal tar. The pitch is a shiny, daik brown to black residue that contains PAHs and their methyl and polymethyl derivatives, as well as heteronuclear compounds. 

Polycyclic pa-le- sl-klik [ISV] (1869) n, adj. Of an organic compound, containing two or more rings, often with pairs of rings sharing two carbon atoms, as in the hydrocarbon anthracene (C14H10). 

The sediment had concentrations of mineral oils ranging from 30 to 293 mg kg" . Qualitative analysis established the presence of hydrocarbon series of the n-alkane type. There was a high presence of phthalate and series C > 20 and C > 30 and cyclohexane derivatives. The nature of n-alkane series indicates pollution with heavy fractions of petroleum. All samples contained polycyclic aromatic hydrocarbons (anthracenes, pyrenes, phenanthrenes, etc.). 

All the dyestuffs mentioned so far had no natural counterparts. However, in 1869 Perkin in England and Heinrich Caro (1834-1910) in Germany independently discovered a method of synthesising alizarin, the natural dye of the madder plant, which had been used since antiquity. The starting material for the synthesis was the hydrocarbon anthracene. This is present in the least volatile fraction of coal tar, for which hitherto there had been very little use. Its value now increased enormously. 

FIG U RE 3.8 Fries structures for a selection of smaller benzenoid hydrocarbons. Anthracene, pyrene, and ovalene have two Fries structures. 

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