Naphthalene and its derivatives

The nitration of naphthalene and its derivatives has been much studied, 

The tendency towards a-substitution is also seen in the reactions of naphthalene derivatives containing de-activating substituents. Thus, 

1- nitronaphthalene with mixed acid gives 1,5- and 1,8-dinitronaphthalene (with some trinitronaphthalene) in the ratio of about i 2, whilst 

2- nitronaphthalene gives 1,6- and 1,7-dinitronaphthalene (with some 1,3,8-trinitronaphthalene).  

The nitration of naphthalene and its derivatives has been much studied, but quantitative data are still not extensive. Naphthalene itself is nitrated 

Diphenylamine was hydrogenated to dicyclohexylamine as its hydrochloride salt over Adams platinum in ethanol at 30°C and 0.3 MPa H2, while the hydrogenation of triphenylamine in the presence of hydrochloric acid gave a mixture of 50-60% of tri-cyclohexylamine, 8-10% of dicyclohexylamine, and cyclohexane.228 

Usually o.v-dccalin is formed more selectively from tetralin than from naphthalene. Baker and Schuetz obtained a mixture of 77% cis- and 23% frans-decalin in the hydrogenation of naphthalene over Adams platinum oxide in acetic acid-ether at 25°C and 12.8 MPa H2, while cA-decalin was obtained exclusively in the hydrogenation of tetralin in acetic acid under similar conditions.23 

Weitkamp hydrogenated naphthalene and tetralin over supported platinum metals at 6.8 MPa H2.234 The selectivity of the catalysts for formation of trans-decalin from naphthalene decreased in the following order Pd-C (52%) (at 100°C) Rh-Al203 (-17.5%) (at 25°C) Pt-Al203 (-12%) (at 200°C) Ir-C (-8%) (at 25°C) Ru-C (5%) (at 25°C). The selectivity for /rau.v-dccalin from tetralin (25°C) was in the order Pd-C (53%) Pt-C (16%) Rh-C (11%) Ir-C (7.5%) Ru-C (5.5%). Thus, Ru-C was the most selective for the formation of cA-decalin and Ir-C was slightly less selective than Ru-C, while definitely larger amounts of frans-decalin were formed over Pd-C. 

In the hydrogenation of 1-alkyl-substituted naphthalenes over Pd-C, the proportion of hydrogenation of the substituted ring increases with increasing bulkiness of the 1-alkyl groups, as shown in eq. 11.67.238 The effect of the substituents is most pronounced in 1-Z-butylnaphthalene, where the ring with f-butyl was hydrogenated 

The ratio of the ar-2-TL/ac-2-TL formed, however, varies considerably with the presence or absence of alkaline substances and also with solvents. Stork showed that in the presence of small amounts of sodium hydroxide or triethylamine ac-2-TL was obtained in more than 60% yields in the hydrogenation over Raney Ni in ethanol (eq. 11.70), while in neutral ethanol or the ethanol acidified with addition of acetic acid ar-2-TL became the predominant product (57-68% yield).239 In one patent, ar-2-TL was obtained in an 83.3 mol% yield by hydrogenation of 2-naphthol over Raney in EtOH-AcOH adjusted to pH 2 at 110°C and 1.96 MPa H2.241 

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The following isomers are described by Beilstein. These compds are weaker expls than the corresponding dinitronaphthalenes (see under Naphthalene and its Derivatives in this Vol)... 

Uses. Naphthalene and its derivatives find uses as starting materials for the prepn of dyestuffs, pharmaceuticals, pest control agents, and expls(Ref 11). It is one ingredient in the expl Dahmenite A ... 

Bunce NJ, L Liu, J Zhu, DA Lane (1997) Reaction of naphthalene and its derivatives with hydroxyl radicals in the gas phase. Environ Sci Technol 31 2252-2259. 

The aerobic degradation of naphthalene and its derivatives has been extensively examined, so that the pathway, biochemistry, and genetics are well established. 

The effect of the substitution of a heavy-atom directly onto the nucleus of aromatic compounds (internal heavy-atom effect) on intercombinational radiative and nonradiative processes can be seen by examination of experimental data obtained for naphthalene and its derivatives. The data obtained by Ermolaev and Svitashev<104) and analyzed by Birks(24) to obtain individual rate constants for the various processes are collected in Table 5.9. 

Substituent groups have a marked effect on the fluorescence quantum yield of many compounds. Electron-donating groups such as -OH, -NH2 and -NR.2 enhance the fluorescence efficiency, whereas electron-withdrawing groups such as -CHO, -C02H and -N02 reduce the fluorescence quantum yield, as shown by naphthalene and its derivatives in Table 4.3. 

Table 4.3 The effect of substituent groups on fluorescence efficiency of naphthalene and its derivatives. Fluorescence quantum yields measured in fluid solution at room temperature...

There is a substantial entropy decrease AS associated with intermolecular excimer formation, as given in the tabulation by Birks 71). For all solvents (except 95% ethanol 75), the value AS ss —20 cal/mole-K was observed for naphthalene and its derivatives. For comparison, the entropy of fusion of unsubstituted aromatic hydrocarbons such as naphthalene falls in the range of —8 to —15 e.u. The large loss of entropy in the intermolecular excimer formation process indicates a very constrained symmetric structure. 

The quantum yields and decay rates of the intermolecular excimer of naphthalene and its derivatives are given in Table 8. The solvent ethanol water 95 5 v/v is one of the few solvents in which the fluorescence of these compounds has been completely characterized. Examination of the values of kD and QM for other solvents shows that 95 % EtOH does not belong in the same class as the hydrocarbon solvents, or even anhydrous ethahol. In the latter solvents, kD/kM falls between 0.8 for 1,6-dimethylnaphthalene and 1.4 for naphthalene. Although the quantity k /k has been measured only once for a naphthyl compound in a hydrocarbon solvent (see Table 5), the values 0.3 and 0.4 seem appropriate for 1,6-dimethylnaphthalene and naphthalene, respectively, in hydrocarbon solvents. Since QD/QM = (kpD/kpM) -s-(kD/kM), we obtain QD/QM = 0.4 for 1,6-dimethylnaphthalene and 0.3 for naphthalene. The intrinsic quantum yield ratio as determined in 95 % EtOH solvent is about seven... 

It is not possible at the present time to give an exhaustive explanation of all the properties of naphthalene and its derivatives. However, the application of quantum mechanics does enable certain empirical rules to be explained theoretically. In order to do this there is no need to reject the Erlenmeyer formula for naphthalene, but only to consider the additional properties due to the resonance in the two six membered rings. 

Consensus on nomenclature had been reached by the 1890s. Aniline was the parent of its derivatives, though sulfonic acids were considered derivatives of benzene, such as aminobenzenesulfonic acid. The prefix amino- was added to naphthalene and its derivatives. Many trivial names came into use, particularly for aminonaphthalenesulfonic acids, found in both academic and industrial research laboratories. Though IUPAC convention now numbers amino aryl compounds according to the parent hydrocarbon, the earlier system of numbering has often been retained, since some names include the positions of substituents at carbon atoms numbered according to the older systems. 

Naphthalene and its derivatives are one of the more dominant aromatics present in various diesel and jet fuel feedstocks. Therefore, several investigators have reported the influence of naphthalene on HDS of model compounds. One of the first reports was by Lo who found naphthalene to weakly inhibit the conversion and selectivity of the HDS of DBT. Similarly, LaVopa and Satterfield found little effect of naphthalene and phenanthrene on the HDS of thiophene. Other researchers have, however, found naphthalene to be a stronger inhibitor of HDS activ-ity. Nagai and Kabe, in fact, found naphthalene to significantly reduce catalyst selectivity for the hydrogenation pathway.Isoda et al., on the basis of similar selectivity inhibition, concluded that naphthalene severely inhibits the hydrogenation active sites in a... 

Chemically, kerosene is a mixture of hydrocarbons, and the constituents include n-dodecane n-Ci 2, alkyl benzenes, and naphthalene and its derivatives (ASTM D-1840). The chemical composition depends on its source and has a high number (>100,000) of isomers that are possible (Table 7.2). The actual number of compounds in kerosene is much lower, and there are claims to less than 100 constituents but that, again, is source- and process dependent. 

Selective dkylation of benzene and alkylbenzenes over various zeolites has been studied extensively since the 1960 s, as summarized in many reports [Venuto and Landis, 1968 Yashima et al., 1970 Kaeding et al., 1981 Haag, 1984 Chen and Garwood, 1986 Yashima, 1988 Dwyer, 1991 Bhat et al., 1992 Chen et al., 1996 Xu et al., 1996]. However, until recently, little attention has been paid to selective alkylation of two-ring aromatics such as naphthalene and biphenyl. Naphthalene and its derivatives are rich in liquids derived from coals via carbonization, pyrolysis and liquefaction. Due to the need for monomers for making the advanced polymer materials shown in Scheme I, (3-selective naphthalene alkylation has become an important subject. In particular, 2,6-dialkyl substituted naphthalene (2,6-DAN) is needed now for making the monomers for PEN, PBN and LCPs shown in Scheme 1. 

Photopolymerization of acrylonitrile in the presence of naphthalene and its derivatives,19 of 9-vinylanthracenes,20 and of sulphonyl activators for dye-photosensitized polymerization,21 and the polymerization of MMA photo-initiated by anthraquinone (AQ) and 2-t-butylanthraquinone22 have been reported. Some of the important steps in this latter process are shown in reactions... 

The electronic absorption spectra of the ions from protonation of naphthalene and its derivatives are listed in Table 36. The molecular-orbital calculations according to the SCF method have led to the conclusion that the spectra correspond to the ions resulting from the addition of the proton at the a-position of the naphthalene ring. Protonation at the p-position should have resulted in a long-vrave absorption... 

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