Phenanthrenes => naphthalenes

The complexes Cr(CO)3L, with L = phenanthrene, naphthalene, or anthracene, are more active for diene hydrogenation than with L = substituted benzenes (see also Section VIII), and this is attributed to an easier displacement of the arene by the diene substrate, the phenanthrene type being asymmetrically bonded, having two longer and more readily cleaved chromium-carbon bonds (198, 199). 

P-Type Delayed Fluorescence anthracene, phenanthrene, naphthalene, pyrene, acenaphthene, fluoranthene, and 3 4-benzpyrene. 

Sensitized P-Type Delayed Fluorescence phenanthrene/anthracene, anthracene/naphthacene, phenanthrene/naphthalene, proflavine hydro-chloride/anthracene. Undoubtedly, many more examples will soon be found. 

Parker and Hatchard have shown that sensitized fluorescence may be observed following triplet-triplet energy transfer.63 With the donor-acceptor pair phenanthrene-naphthalene in ethanol solution, sensitized anti-Stokes delayed fluorescence was obtained, the most energetic quanta emitted being 5 kcal.mole-1 greater than the exciting light.60... 

Mostly, electron carriers used in reduction processes are ardical anions of commercially available acceptors like nitroaromatic compounds, polyaromatic rings, aromatic heterocycles, and ketones (dinitrobenzene, benzophenones, acridine, fluorenone, diphenyl anthracene, anthracene, phenanthrene, naphthalene, and so on). Table 1 exhibits some possible mediators within a large cathodic potential range. 

The initial rate of hydrogenation of fused polycyclic aromatics increases with the number of rings present phenanthrene > naphthalene > benzene. Only one ring is generally saturated at a time. This partial hydrogenation is accomplished because... 

The exciplexes formed between excited arenes (e.g. phenanthrene, naphthalene, 2,3-dimethylnaphthalene) and the acceptor 1,4-dicyanobenzene in ether solutions containing 1-propylamine are quenched by the addition of tetramethylammonium tetrafluoroborate, and products of addition, (129)-(131), are obtained. The authors suggest that under the relatively non-polar conditions the added salt promotes charge separation in the exciplex so that the amine can attack the arene radical cation. 

Dehalogenation N,N-Dimethylaniline. Disodium phenanthrene. Naphthalene-sodium. Sodium-/-Butanol-Tetrahydrofurane. Sodium telluride. Tin. Tri-n-butyltinhydride. 

Coal tar constituents present in surface waters may be degraded by direct and indirect photolysis. Estimated aqueous photolysis half-lives of 8.4, 71, and 21 hours have been reported for phenanthrene, naphthalene and fluoranthene, respectively (Zepp and Schlotzhauer 1979). Other coal tar constituents which may undergo aqueous photolysis are acenaphthalene, anthracene, benzene, quinoline, phenol, cresol, and carbazide. In a microcosm study, PAHs leached from creosote-impregnated wood pilings were degraded in aquatic environments by photolysis and microbial degradation, while sorption to sediment was not significant (Bestari et al. 1998). Photolysis in water is not expected to be a major route of the environmental fate of creosote constituents, particularly for the less soluble compounds. 

Kurnik and Reid described the solubility behavior for a number of binary solid mixtures consisting of combinations of phenanthrene, naphthalene, benzoic acid, and 2,3- and 2,6-dimethylnaphthalene extracted with supercritical carbon dioxide and ethylene. They found that for a binary solid mixture, the presence of one of the solid components solubilized in the SCF-rich phase enhances the solubility of the other solid component in the SCF-rich phase. They suggest that the first solid component acts as an entrainer, or so-called cosolvent, to enhance the solvent power of the pure SCF. For example, they... 

Weigang95 has measured the solvent shifts for all the electronic transitions of phenanthrene, naphthalene and azulene in a series of paraffin hydrocarbon solvents. The effect of branching and cyclization was studied by the inclusion of various structural isomers. Normal hydrocarbons give remarkable linear shifts, and these shifts fit well into the McRae theory87. The corresponding non-cyclic branched and cyclic hydrocarbons produce lesser shifts. These small shifts have been attributed to the change in the physical conformation of the molecule and the resultant opportunity for closer interactions with the chromophore. 

Chrysene. Orlow and Lichatschew (8) found that with 70 atm H2 the hydrogenolysis reaction products (by weight) were 25% methane, 35% coke, with the remaining 40% containing phenanthrene, naphthalene, benzene, and various hydrides of each. The pyrolysis products were hydrogen and methane with traces of acetylene in the gas and solid carbon. 

DCB". Secondary electron transfer then occurs from the allylsilane D to ArH or the Jt-complexation of ArH wifli D, [ArH D]. The radical cation species D or [ArH D] reacts to produce the allyl radical, which reacts wifli /i-DCB to give the substitution product shown in Scheme 2. Aromatic hydrocarbons such as phenanthrene, naphthalene, triphenylene, and />-terphenyl (Table 3) are effective in the redox photosensitization in the photosubstitution of E)CB by allyltrimethylsilane. ... 

Decarboxylation of A -Boc-L-valine has been performed in polar solvents, using electron acceptors such as dicyanobenzenes, methyl 4-cyanobenzoate, and 1,4-dicyanonaphthalene as photosensitizers, in combination with several arenes (phenanthrene, naphthalene, 1-methylnaphthalene, biphenyl, triphe-nylene, and chrysene) as co-sensitizers. The best result is achieved using biphenyl and 1,4-dicyanonaphthalene in aqueous acetonitrile. This type of reaction has been applied to the photodecarboxylation of A -Boc protected amino acids and other free carboxylic acids, in the presence of thiol and a small amount of D2O, to obtain products with high deuterium content. 

The complex tm 5,/ra 5-hexa-2,4-dienetetracarbonylchromium has been shown to be an intermediate in the photocatalytic hydrogenation of tram,rra/zj-hexa-2,4-diene with [Cr(CO)8]. The complexes [Cr(CO)3(L)] (L=phenanthrene, naphthalene, or anthracene) are much more active in the catalysis of diene hydrogenation than typical arenetricarbonylchromium complexes in addition to which induction times are significantly lower. This can be correlated with the asymmetry of the Cr—arene bonding which may facilitate formation of an intermediate (47) during the induction period. ... 

Recently a suitable combination of a coordinating solvent (THF, acetone, dioxane) and an arene compound with a kinetically labile i-bonded ligand (anthracene, phenanthrene, naphthalene) that undergo the expected arene displacement reaction under milder conditions has been reported by Yag-upsky and Cai s (1975). 

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