Naphthalene perylene reduction

PERYLENE REDUCTION IN THE PRESENCE OF NAPHTHALENE. The chemistry that we have discussed is similar to that of Sternberg and co-workers (1, 2) in using an excess of potassium metal in THF at room temperature. In the Sternberg and co-workers approach, however, naphthalene was used to transfer electrons from potassium metal to the substrate under investigation whether it was a fossil fuel, such as coal (2), or a model compound, such as dibenzothiophene (8). Thus, the results of our work on the direct reduction of perylene by K° might differ from results of a reaction in which naphthalene is present. 

Fig. 3 Electrochemical and homogeneous standard free energies of activation for self-exchange in the reduction of aromatic hydrocarbons in iV.A -dimethylformamide as a function of their equivalent hard sphere radius, a. 1, Benzonitrile 2, 4-cyanopyridine 3, o-toluonitrile 4, w-toluonitrile 5, p-toluonitrile 6, phthalonitrile 7, terephthalonitrile 8, nitrobenzene 9, w-dinitrobenzene 10, p-dinitrobenzene 11, w-nitrobenzonitrile 12, dibenzofuran 13, dibenzothiophene 14, p-naphthoquinone 15, anthracene 16, perylene 17, naphthalene 18, tra 5-stilbene. Solid lines denote theoretical predictions. (Adapted from Kojima and Bard, 1975.)...

It is clear that deuterium as a substituent has the electron-donating effect. In other words, it can decrease electron affinity of the whole molecule. Potentials of reversible one-electron reduction for naphthalene, anthracene, pyrene, perylene, and their perdeuteriated counterparts indicate that the counterparts exhibit slightly more negative potentials (Goodnow and Kaifer 1990, Morris and Smith 1991). For example, the measurable differences in the reduction potentials are equal to -13 mV for the pair of naphthalene-naphthalene-dj or -12 mV for the pair of anthracene-anthracene-djo. The possible experimental error does not exceed 2 mV (Morris and Smith 1991). In another example, in DMF with 0.1 M n-Bu4NPFg, the deuterated pyrenes were invariably found to be more difficult to reduce than pyrene itself. The largest difference observed, 12.4 mV, was between perdeuteriated pyrene and pyrene bearing no deuterium at all with standard deviations between 0.2 and 0.4 mV (Hammerich et al. 1996). 

Reduction of trichloroethylene by a series of well-characterized outer-sphere electron-transfer reagents, viz. the radical anions of naphthalene, pyrene, perylene, decamethylcobaltocene, and cobaltocene, resulted in the formation of cis- and trans-dichloroethylene in ratio varying from 0.87 to 4.5, whereas in the reduction by vitamin B12, the ratio was 30 1. This indicated that reduction with vitamin B12 occurs with a non-outer-sphere electron-transfer mechanism. A mechanism involving initial formation of a radical ion followed by an ejection of a chloride to give d.v-dichlorovinyl radical and franx-dichlorovinyl radical has been proposed.284... 

The addition of alkyl halides to aromatic anion radicals, generated by alkali metal reduction in etheral solvents, was already known in the 1950s [176] and was reviewed by Garst in 1971 [177]. The first electrochemical analogue was observed by Lund et al. [178]. These authors cathodically reduced hydrocarbons such as naphthalene, anthracene, stilbene [128,129], and perylene [130] in the presence of alkyl halides and isolated hydrogenated and alkylated products. Similar reactions are observed when the halides are replaced by ammonium or sulfonium [179]. 

Catalytic hydrogenations over CojfCOjg (using Hj and CO) or with stoichiometric quantities of preformed hydridocarbonyl complex CoH(CO)4 are useful for the partial selective reductions of polycyclic aromatic compounds. Isolated benzene rings are not affected. Naphthalene is reduced to tetralin, at 200°C under a pressure of 20 X 10 kPa and anthracene to 9,10-dihydroanthracene (99%). The substituted phenanthrene nucleus is stable under these conditions as illustrated by hydrogenation of perylene 1 and pyrene 2. ... 

The most widely used reductive degradation methods are zinc distillation and sodium amalgam reduction. Fused aromatic structures (methyl substituted naphthalene, anthracene, pyrene, and perylene) are the major digest products of this reduction of humic substances. 

Reductive Remediation of Nonhalogenated Molecules. Na/NHa treatments can also destroy nonhalogenated hazardous conqraunds. Three classes pollutants will be mentioned here polynuclear aromatic hydrocarbons (PNAs), nitro- and nitrate-type explosive wastes and chemical warfare agents. The treatment of neat sanq>les of PNAs leads to destmction efficiencies of 99.99% for many of these conq)ounds including such examples as acenaphthene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[g,h,l]perylene, chrysene, fluorandiene, fluorine, naphdialene and phenanthrene. With the exception of naphthalene and anthracene, conq)lex product mixtures are formed. Radical anion formation followed by protonation occurs sequentially leading to dihydro, tetrahydro and further reduced products (see Scheme 3). Depending on the reaction conditions, dimerization of intermediate radicals can occur to give dimers in various states of reduction. 

Radical anions have been obtained electrochemically from condensed aromatic systems by electrolytic reduction of naphthalene [62, 117], 1,5-naphthalenedisulfonate [118], anthracene [54, 55, 62, 117-119], 9,10-diphenylanthracene [69, 120], phenanthrene [62, 117], tetracene [62, 118, 121], pyrene [62], pentacene [62], and perylene [62]. 

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