Anthracene and naphthalene

Results are given for k = 0 and several different directions of k. For purposes of comparison, the values calculated using the dipole approximation for all interactions with k perpendicular to the face (001) are also given in Table 3.5. Below, to give an impression of the state of art, we mention in some detail, for 

Energy of the two exciton branches of the 0-0 component of the 3800 A transition for k normal to faces (001), (010), and (100). Reprinted with permission from Philpott (81). Copyright 1971, American Institute of Physics. 

The results of calculations of exciton bands in the anthracene crystal in the dipole-dipole approximation are shown on Fig. 3.7. The letters a, b, c on the Fig. 3.7 indicate the orientation of the transition dipole moment. The results of calculations of exciton bands for the 2500-A electronic transition can also be found in the quoted paper. 

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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. 

Quinizarin.—1 4-dihydroxyanthraquinone is of no use as a dye it has been found, as a general rule, that only those polyhydroxyquinones of the anthracene and naphthalene series (naphthazarin) which have their adjacent OH-groups in positions adjoining the carbonyl group are capable of forming colour lakes. 

In contrast to the -conjugated probe architecture utilizing an ICT process, the number of anion probes that rely on the fluorophore-spacer-receptor design and an active PET process is abundant [72], Again, anthracene and naphthalene... 

We employed various substrates to check for MFO in two bivalve species, a salt water mussel (Mytilus edulis) and a fresh water clam (Anodonta sp). Cytochrome P-450 was also studied. Organisms were exposed to 100 PPM Venezuelan crude in a stagnant system for up to one month. Enzyme assays were carried out with digestive gland 9000 g homogenates (17) and cytochrome P-450 analysis, with microsomes (21). The hydrocarbon substrates investigated included 1I+C-labelled benzo(a)pyrene, fluorene, anthracene, and naphthalene. The method used for separation of BP metabolites by thin layer radiochromatography has been described (7). The metabolite detection method for the other aromatic hydrocarbons was essentially the same except methylene chloride was used as metabolite extractant as well as TLC developer. Besides the hydrocarbon substrates, we also checked for other MFO reactions, N-dealkylase with C-imipramine (22) and 0-dealkylase with ethoxycoumarin (15). 

For a molecular crystal, the internal modes tend to be q independent and thus appear as horizontal lines in Fig. 2.1 n is then equal to the number of molecules M in the cell, leading to a considerable simplification. The resulting dynamical matrix has 6M x 6M elements, considering both translational and rotational motions, and atom-atom potential functions may be used for its evaluation. Dispersion curves obtained in this manner for anthracene and naphthalene, are illustrated in Fig. 2.2. 

Intramolecular Photocycloaddition of N—P4—A. Although the photocycloaddition of anthracene [85-100] and that of naphthalene [65-67,80-82] have been extensively studied, until recently relatively little has been reported on the cross-photocycloaddition between an anthracene and a naphthalene moiety [101-110], The main reason for this is the large difference in the quantum yields between the photocycloaddition of anthracene and the cross-photocycloaddition of anthracene and naphthalene. Thus, bichromophoric molecules with anthryl as one chromophore and naphthyl as the other generally undergo intermolecular an-thryl-anthryl cycloaddition rather than intramolecular cross-cycloaddition when irradiated. 

The pairing theorem requires that the HOMOs and LUMOs of the alternant molecules anthracene and naphthalene are localized on the same atoms this is not the case for the nonalternant azulene. For the detailed calculations concerning the colordetermining interelectronic repulsion, see the paper by Michl and Thulstrup.8... 

Solvents with a large donor number tend to associate with hydrogen donors such as water or chloroform. This may explain the finding19 that the stability of the anthracene and naphthalene anion radicals in the presence of small amounts of added water is greater in dimethylformamide (DMF) and dimethyl sulfoxide (Me2SO) than in acetonitrile. This stability order parallels the donor numbers of the solvents and reflects the greater tendency of DMF and Me2SO to associate with water. The latter causes the protons on water to be less... 

Radical cations have also been trapped with the hydride ion. Irradiation of aromatic hydrocarbons such as phenanthrene, anthracene and naphthalene in aqueous acetonitrile containing sodium borohydride and an electron acceptor produces the dihydroarenes (Yasuda et ai, 1981b). With monoalkyl naphthalenes reduction in both the unsubstituted and substituted rings occurs... 

Semiempirical calculations of B are reported [164] for the Ag mode dependence on the applied static electric field for adsorbed CO, ethylene, naphthalene, anthracene and TCNQ-. It was observed that for systems with high polarizability such as TCNQ and anthracene, a good fit between B and the square of the electric field is obtained, while for CO a linearity is observed only at very high electric fields (>2x10 Vcm ). These results are used to explain the breakdown of the surface selection rule for the C = C symmetric stretch of flat adsorbed molecules like ethylene, anthracene and naphthalene at platinum electrodes. 

The combination of a large number of chemical resolution and assignment studies (Table 3) of benzo-ring /rans-dihydrodiols along with studies designed to define the stereochemical course of metabolism of benzo[a]pyrene, ° benz[a]-anthracene, chrysene, phenanthrene, benzo[c]phenanthrene, anthracene, and naphthalene has led to the conclusion that the combined action of cytochrome P450c and epoxide hydrolase has a marked preference for the formation of (—)-(R,R)-dihydrodiols. This result pertains even when the initially... 

Two-thirds of 105 sediment samples collected throughout Florida during the summers of 1989 and 1990 from sites known or suspected to be contaminated with priority pollutants were found to contain at least one of 15 PAH target analytes (Jacobs et al. 1993). Pyrene was detected most frequently (61% of samples) dibenz[a.h]anthracene and naphthalene were detected least frequently (4% of samples). Total PAH concentrations ranged from below the detection limit to 1,090 mg/kg. Mean concentrations for individual PAHs ranged from 0.87 mg/kg (dibenz[a,h]anthracene and naphthalene) to 30.8 mg/kg (acenaphthene). 

A limited number of experiments were conducted to evaluate the last two possibilities. First, the take-up solvent for two test solutes, anthracene and naphthalene, was cyclopentane (with solution concentrations still about 1 mg/mL and injection aliquots still about 0.3 - 0.5 pL into a 20vL loop) instead of 2-methoxy-ethanol. The distortion persisted even when a gentle stream of air was used after aliquot deposition in the sampling loop to blow off the take-up solvent. Furthermore, the onset of the distortion for naphthalene occurred at a lower carbon dioxide density than for anthracene. When the column was changed to a partially chemically deactivated column, Hypersll SAS, where short alkyl chains are bonded to active sites, onsets of peak distortion for anthracene and for naphthalene were shifted to lower carbon dioxide densities (and still different from each other) than for the fully active Hypersll SIL adsorption column. Only slight peak distortion was observed for a Hypersll ODS column at even lower column midpoint densities (0.33 g/mL with the back pressure at 1170 psig, the FLOW setting at 1.90 mL/min, and 40 C distortion was observed for only anthracene and not naphthalene). 

Albini, A., Fasani, E., Faiardi, D., Charge transfer and Exciplex Pathway in the Photocycloaddition of 9 Anthracenecarbonitrile with Anthracene and Naphthalenes, J. Org. Chem. 1987, 52, 155 157. 

As shown by Choi et al. (40) contributions of ionized states and of the exchange interaction to the width of triplet excitonic band are of the same order of magnitude. When ionized states are taken into account, the Davydov splitting in anthracene and naphthalene increases by about 50%. 

Absolute rate constants have been determined for aromatic triplet formation in acetone solutions of several aromatic compounds (5, 30). The formation curves were observed directly for anthracene and naphthalene triplet (5) and for diphenyl triplet. These rate curves were found to fit a first order rate law, and were interpreted as a bimolecular energy transfer process from a state of the solvent molecule which is probably the triplet, that is, by Reaction 11. These rate constants, as well as the triplet yields, are listed in Table VI. The rate constants for anthracene and naphthalene triplet formation appear to correspond to diffusion controlled rate constants. Two further points are of interest, which are in contrast with observations in other systems which will be discussed. In acetone, most of the yield of aromatic triplet (at concentrations of the aromatic compound of 5 X 10"3M or lower) is formed in diffusional processes such as collisional energy transfer. Any fast formation appears... 

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