Naphthenes

Naphthenes, hydrocarbons of the general formula C_nH_2n, possessing the properties of saturated compounds; they belong to alicyclic compounds, and are contained mainly in Caucasian petroleum, from which N. from C₅H₁₀ to C₁₅H₃₀ have been isolated. Naphthenes are liquids with a petroleum odor; their boiling points and chemical properties are close to the boiling points and chemical properties of paraffin hydrocarbons with the same number of carbon atoms. Naphthenes do not react with H₂SO₄; upon nitration they give nitro derivatives; upon the action of chlorine on naphthenes, chloronaphthenes are obtained, from which by the removal of halohydric acid, naphthylenes (cyclic hydrocarbons with one ethylene bond) are formed: C_nH_2n-Cl + HCl = C_nH_2n-2. With bromine, naphthenes give aromatic bromo derivatives; upon heating with I or S, they liberate HI or H₂S and form aromatic hydrocarbons. The corresponding naphthenic acids, so-called, are known, the structure of which, with minor exceptions, has not been established. Naphthenic acids are used for denaturing alcohol, and in the form of salts as impurities in soap, as well as emulsifiers; naphthenic soaps are a disinfectant.