Decahydronaphthalene

FIGURE 1.10 Two isomers of decahydronaphthalene, or bicyclo[4.4.0]decane. (a) Trans isomer b) cis isomer. 

The bicyclic compound decahydronaphthalene, or bicyclo[4.4.0]decane, has two fused six-mem-bered rings. It exists in cis and trans forms (see Fig. 1.10), as determined by the configurations at the bridgehead carbon atoms. Both cis- and rran -decahydronaphthaiene can be constructed with two chair conformations. 

Naphthalene is very slightly soluble in water but is appreciably soluble in many organic solvents, eg, 1,2,3,4-tetrahydronaphthalene, phenols, ethers, carbon disulfide, chloroform, ben2ene, coal-tar naphtha, carbon tetrachloride, acetone, and decahydronaphthalene. Selected solubiUty data are presented in Table 4. 

Hyd.rogena.tlon. Hydrogen is added to the naphthalene nucleus by reagents that do not affect ben2ene. Two, four, six, eight, or ten hydrogen atoms may add. Of these, only the tetra- and decahydronaphthalenes are commercially significant. In addition to the commercially important... 

Tetrahydronaphthalene [119-64-2] (Tetralin) is a water-white Hquid that is insoluble in water, slightly soluble in methyl alcohol, and completely soluble in other monohydric alcohols, ethyl ether, and most other organic solvents. It is a powerhil solvent for oils, resins, waxes, mbber, asphalt, and aromatic hydrocarbons, eg, naphthalene and anthracene. Its high flash point and low vapor pressure make it usehil in the manufacture of paints, lacquers, and varnishes for cleaning printing ink from rollers and type in the manufacture of shoe creams and floor waxes as a solvent in the textile industry and for the removal of naphthalene deposits in gas-distribution systems (25). The commercial product typically has a tetrahydronaphthalene content of >97 wt%, with some decahydronaphthalene and naphthalene as the principal impurities. 

Further hydrogenation under pressure in the presence of a nickel catalyst gives a mixture of cis- and /n j -decahydronaphthalene [493-02-7] (Decalin). 

Decahydronaphthalene [91-17-8] (Decalin) is the product of complete hydrogenation of naphthalene. Like Tetralin, it is a clear, colorless Hquid with... 

The uses of decahydronaphthalene are similar to those of 1,2,3,4-tetrahydronaphthalene. Mixtures of the two are used for certain appHcations where a synergistic solvency effect is noted. 

Some selected chemical and physical properties of 1,2,3,4-tetrahydronaphthalene and the decahydronaphthalenes are Hsted in Table 5. 

Miscellaneous uses include several organic compounds and intermediates, eg, 1-naphthalenol, 1-naphthylamine [134-32-7] 1,2,3,4-tetrahydronaphthalene, decahydronaphthalene, and chlorinated naphthalenes. 

In addition to the ahphatic (chain) molecules, the saturates contain cycloalkanes, called naphthenes, having mainly five or six carbons in the ring (Fig. 5). Methyl derivatives of cyclopentane and cyclohexane ate commonly found in greater quantity than the parent unsubstituted stmctures and can be present at levels above 2% (2). Fused-ting dicycloalkanes such as decahydronaphthalenes (decalins) and hexahydroindans are also common, but nonfused bicyhc naphthenes, eg, cyclohexyl cyclohexane, are not. 

Explosions due to the presence of peroxides formed by aerial oxidation of ethers and tetrahydrofuran, decahydronaphthalene, acrylonitrile, styrene and related compounds. 

Chemical Designations - Synonyms Bicyclo [4.4.0] Decane Naphthalane Perhydronaphthlene Dec Decalin De Kalin Naphthane sic- or trans-Decahydronaphthalene Chemical Formula CjoHu. Observable Characteristics - Physical State (as normally shipped) Liquid Color Colorless Odor Aromatic, like turpentine mild, characteristic. 

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