Naphthalene, sodium-liquid

Alkyl Naphthalene Sodium Sulfonate % Active 50 Form Liquid... 

Naphthalene sodium prepared in dimethyl ether or another appropriate solvent, or metallic sodium dissolved in liquid ammonia or dimethyl sulfoxide, is used to treat polyfluorocarbon and other resins to promote adhesion (138—140). Sodium, usually in dispersed form, is used to desulfurize a variety of hydrocarbon stocks (141). The process is most useful for removal of small amounts of sulfur remaining after hydrodesulfurization. 

Along with metals, the threshold of forced cold brittleness is also observed in solids of all other kinds, that is, covalent crystals (e.g., in the system germanium-gold), ionic substances (e.g., sodium chloride in the melted aluminum chloride), and molecular crystals (e.g., naphthalene in liquid hydrocarbon). In the other words, there is only a limited interval of optimum temperatures in which the Rehbinder effect is observed. At temperatures that are too low, the effect is retarded by the excessive starting brittleness and the solidification of the medium, while at temperatures that are too high, it is retarded by the excessive plasticity of the solid. This temperature dependence is one of the principal features of the Rehbinder effect, which makes it very different from the chanical or corrosive action of the medium, both of which intensify as temperature increases. 

A distinction between a solid and liquid is often made in terms of the presence of a crystalline or noncrystalline state. Crystals have definite lines of cleavage and an orderly geometric structure. Thus, diamond is crystalline and solid, while glass is not. The hardness of the substance does not determine the physical state. Soft crystals such as sodium metal, naphthalene, and ice are solid while supercooled glycerine or supercooled quartz are not crystalline and are better considered to be supercooled liquids. Intermediate between the solid and liquid are liquid crystals, which have orderly structures in one or two dimensions,4 but not all three. These demonstrate that science is never as simple as we try to make it through our classification schemes. We will see that thermodynamics handles such exceptions with ease. 

Many expensive reductions such as the Birch reduction of naphthalene to isotetralin, benzene to cyclohexene, with metallic sodium and liquid ammonia, or reduction with LiAlHa, can generally be carried out electrochemically at much lower cost and under safe conditions. Electrochemical processes allow fluorinations to be carried out without using fluorine gas. Conducting polymers have been made by electrochemical processes which operate under ambient conditions, and the polymer can be synthesized, doped and shaped in film form in a single step. 

Chromic acid and chromium trioxide Chlorine Acetic acid, naphthalene, camphor, glycerol, turpentine, alcohol or other flammable liquids Ammonia, acetylene, butadiene, butane or other petroleum gases, hydrogen, sodium carbide, turpentine, benzene or finely divided metals... 

The radical-anion proceeds to propagate in the same manner as discussed above for initiation by sodium naphthalene. (Polymerizations in liquid ammonia are very different from those in organic solvents in that free ions probably constitute the major portion of propagating species.)... 

Naphthalene 1,2-oxide (45) has been obtained by bromination (NBS)-dehydrobromination (DBN) of tetralin 1,2-epoxide (115).57 Sodium in liquid ammonia gives diepoxide 116 from 117.58 Also, the saturated compound 118 with potassium f-butoxide in THF yields the oxaazabis-6-homobenzene system (119, 80%).29... 

When naphthalene is reduced in liquid ammonia by metallic potassium, evaporation of excess ammonia gives the solvated solid potassium naphthalide (K2. NH3. Naphth2). If sodium is used in place of potassium, the product detonates as crystallisation starts. This is attributed to energetic expulsion of ammonia held... 

In place of sodium hydroxide, sodium acetate may be added to the mixture of diazonium salt solution and the aromatic liquid.6 Another variation, introduced by Hodgson and Marsden,6 consists in converting the aryldiazonium chloride to a stabilized diazonium salt by treatment wi,th naphthalene-l-sulfonic acid, naphthalene-1,5-disulfonic acid, or zinc chloride the dried salt is then suspended in an aromatic liquid and treated with sodium acetate and acetic anhydride. 

Neither of these compounds is very soluble in water, but both dissolve in a less polar solvent such as dichloromethane (CH2C12). If this solution is extracted with aqueous sodium hydroxide, the benzoic acid reacts to form a salt that is soluble in the aqueous phase. Therefore, when the two liquids are separated the carboxylic acid salt is in the aqueous phase and the naphthalene remains in the dichloromethane. The compounds have now been separated. To recover the carboxylic acid it is necessary to protonate its conjugate base. This can be accomplished by treating the aqueous solution with a strong acid such as hydrochloric acid. The equilibrium shown in the following equation favors the weaker acid the carboxylic acid which then precipitates from the solution ... 

Chromotropic acid (saturated). To 0-1 g chromotropic acid (1,8-dihydroxy-naphthalene-3,6-disulphonic acid sodium salt) C, 0H6O8S2Na2 add 5 ml water, mix thoroughly, and use the pure supernatant liquid for the tests. 

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