Naphthalene compounds

N. Donaldson, The Chemistry and Technology of Naphthalene Compounds, Edward Arnold Pubhshers, London, 1958, pp. 455—473. 

Many different combinations of carboxyflc acid and hydroxyl groups have been tested to form LCPs. An aromatic stmcture (ben2ene, naphthalene, anthracene, etc) is required that has its functional groups symetricaHy arranged on opposite sides of the molecule. Examples are a 1,4-substituted ben2ene compound or 2,6-substituted naphthalene compound. These monomers are often complex and expensive molecules and account for a significant portion... 

Aza-naphthalene compounds offer a variety of positions in addition to the familiar ortho, meta, and para positions. According to Erdmann, the new positions may be named similarly as caM, amphi, ana, epi, pros, and peri on the basis of their effective structural... 

Chemistry and Technology of Naphthalene Compounds , E. Arnold, London (1958), 45 55) B.T. Fedoroff et al, Dictionary of Explosives, Ammunition, and Weapons (German Section) , PATR 2510 (1958), Ger 43 56)... 

Figure 4.34 Peak-pair resolution naps and an overlapping resolution nap for the separation of nine substituted naphthalene compounds by reversed-phase liquid cbrosatography illustrated in Figure 4.33. (Reproduced with permission from ref. 545. Copyright Elsevier Scientific Publishing Co.)...

Benzene and naphthalene compounds can be formylated under Vil-smeir conditions. The formyl compounds, with or without isolating, can be condensed with amino arenes to give leuco compounds. In this reaction, the benzhydrol intermediate is not isolated.21,79,84 86 The reaction is generally carried out in an alcohol solvent such as isopropanol, butanol, or pentanol and an acid catalyst such as hydrochloric acid, sulfuric acid, or methanesul-fonic acid.87 Acetic acid can also be used both as catalyst and as the solvent. Urea sometimes is added as catalyst.84,88 Terephthaldehyde reacts with W-diethyl-3-methylaniline89 and substituted azulenes to give a bis-triphenylmethane21 57 and 58, respectively. 

In order to combat this, the rotating frame Overhauser effect spectroscopy (ROESY) techniques can be employed. An in-depth discussion of how this technique works is outside the remit of this book but suffice to say, in the ROESY methods (1- and 2-D), NOE data is acquired as if in a weak r.f. field rather than in a large, static magnetic field and this assures that all NOEs are present and positive, irrespective of tumbling rate and magnet size. It is possible that some TOCSY correlations can break through in ROESY spectra but these will have opposite phase to the genuine ROESY correlations and so should therefore not be a problem - unless they should overlap accidentally with them. A 2-D ROESY spectrum of the naphthalene compound is shown below (Spectrum 8.6). 

A process, which considered the bio-oxidation of naphthalene compounds using naphthalenes-oxidizing bacteria, was applied for the treatment of gas oil. The quality of the product not only exhibited a sulfur content closed to specifications but also a high lubricity. Description on the used microbial strain was not provided [432],... 

In the SE compartment, PCI (explaining 52.3% of data variance) describes a contamination pattern of PAHs, except for the naphthalene compound. This compound is the most volatile within this group, and presents a slightly different chemical behavior. The pattern of PAHs is detected at high levels in the upper... 

N Donaldson, The chemistry and technology of naphthalene compounds, (London Edward Arnold, 1958). 

While donor substituents assist in ortho and meta protonation, acceptor substituents direct protonation of the primary anion-radicals to the ipso and para positions. It should be emphasized that water treatment of the naphthalene anion-radical in THF leads to 1,4-dihydronaphthalene. Notably, the same treatment of this anion-radical, but o-bound to rhodium, leads to strikingly different results. In the rhodium-naphthalene compound, an unpaired electron is localized in the naphthalene, but no protonation of the naphthalene part takes places on addition of water. Only evolution of hydrogen was observed (Freeh et al. 2006). Being a-bound to rhodium, naphthalene acts as an electron reservoir. The naphthalene anion-radical part reacts with a proton according to the electron-transfer scheme similar to the anion-radicals of aromatic nitro compounds (see Scheme 1.14). 

Fig. 8.22 Fraction of naphthalene concentration due to colloidal entrainment at (a) G = 5 and (b) = 20 s , for naphthalene and naphthalene compounds containing 1,2, or 3 C as side chains, where is the mean shear rate. Reprinted with permission from Sterhng Jr MC, Bonner JS, Page CA, Ernest ANS, Auteniieth RL (2003) Partitioning of crude oil polycyclic aromatic hydrocarbons in aquatic systems. Environ Sci Technol 37 4429 434. Copyright 2003 American Chemical Society...

Perhaps the best-known method of preparing aromatic azo compounds involves the coupling of diazonium salts with sufficiently reactive aromatic compounds such as phenols, aromatic amines, phenyl ethers, the related naphthalene compounds, and even sufficiently reactive aromatic hydrocarbons. Generally, the coupling must be carried out in media which are neutral or slightly basic or which are buffered in the appropriate pH range. The reaction may also be carried out in nonaqueous media. While some primary and secondary aromatic amines initially form an A-azoamine, which may rearrange to the more usual amino-C-azo compound, tertiary amines couple in a normal manner. 

The rate constant kTD for fluorescence of the pyrene intermolecular solution excimer has been found to follow the relation kFD = n2(kFD)n=I, where n is the the refractive index of the solvent69 . The values of kTO for the 1-methylnaphthalene excimer in ethanol at various temperatures are also consistent with the above relation 76). The fact that (kFD)n=I is independent of solvent and temperature indicates that the excimer has a specific structure, according to Birks 69,71). Experimentally, it was observed much earlier that kFM = n2(kFM)n=i for the polycyclic aromatic hydrocarbons, and that k /kp is independent of solvent and temperature. Table 5 shows that agreement between independent investigators of the excimers of naphthalene compounds is not always good, as in the case of 1-methylnaphthalene. 

Table 5. Radiative Rate Parameters for Naphthalene Compounds in Solution at Room Temperature (units of 106 s-1)...

In summary, all available evidence suggests that the intermolecular excimers of naphthalene compounds have a sandwich structure in which the ring planes are parallel and the molecular axes are aligned. While the intermolecular excimer appears to adopt the eclipsed sandwich structure in solution, there may be differences in the structure of excimers constrained by hydrocarbon links or by rigid matrices. These constrained excimers will be considered next. 

The strongly anionic alkali metal naphthalene compounds produced very large amounts of 1.2 (or 3.4) structure. The remainder of the polymer was 1.4-trans. No 1.4-cis polymer was produced. Increasing anionic catalysts such as rubidium and cesium produce even larger amounts of 1.4-trans-polybutadiene. 

The presence of water in the sol ution is essential to the production of oxidized naphthalene compounds. As shown in Fig. 11.9, the reaction rate increased with increase of water content and reached the maximum at a water content of about 6%. 

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