Naphthalene solid metals

As implied by the above treatment, the conversion of A into A7, Met+ is never quantitative. For example, reduction of naphthalene in tetrahydrofaran by sodium yields about 95% of its radical anions at ambient temperature, whereas the yield in diethyl ether is very low, less than 1%. The sodium reduction of biphenyl, a hydrocarbon of lower electron affinity than naphthalene, results only in about 20% conversion in tetrahydrofaran, although nearly 100% reduction may be accomplished in dimethoxy-ethane. Since these processes lead to equilibria, it is immaterial whether they take place on the surface of the metal, being followed by desorption of the product, or whether they proceed homogeneously in a solution saturated by metal atoms and their ionization products, these being replenished from the bulk of the solid metal as the reduction proceeds. 

This direct initiation is rarely utilized because the formation of such a radical-anion through the reaction between a solid (metal) and a liquid (monomer) is generally slow. To overcome this limitation, an organic intermediate that cannot polymerize itself but can accommodate electrons by transfer is generally utiUzed. More often, these intermediates are polycyclic aromatic hydrocarbons for example, naphthalene is commonly used for this purpose the reaction between naphthalene (in solution) and sodium (solid) is schematized hereafter ... 

Finally, it has been possible to obtain LEED patterns from films of molecular solids deposited on a metal-backing. Examples include ice and naphthalene [80] and various phthalocyanines [81]. (The metal backing helps to prevent surface charging.)... 

Many solid substances (camphor, iodine, naphthalene, etc.), are known which are appreciably volatile at ordinary temperatures. Others, such as the metals, are apparently quite fixed, but they probably possess a definite, although very small vapour-pressure, even at ordinary temperatures. Thus, if magnesium is heated to 550° for a few hours in a magnesia boat enclosed in a vacuous tube it sublimes in beautiful crystals on the cool part of the tube. The vaporisation of a solid without previous fusion is called sublimation the vapour-pressure (like the vapour-pressure of a liquid), is definite for each temperature, is independent of i the volume of the vapour space, and increases with rise of temperature. 

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. 

TEM-EDS and XPS analyses were conducted on Co/MgO catalysts. The results of surface analyses showed that Co metal is not supported on the MgO as particles, but covers MgO surface in the case of 12 wt.% Co/MgO calcined at 873 K followed by reduction. After the reduction of catalyst at 1173 K, both cobalt oxide and CoO-MgO solid solution are observed on the surface of catalyst. In the steam reforming of naphthalene, two types of coke deposited on the surface of catalyst are observed. These are assigned to film-like and graphite type carbon by TPO analysis. 

When naphthalene is reduced in liquid ammonia by metallic potassium, evaporation of excess ammonia gives the solvated solid potassium naphthalide (K2 ... 

This approach frequently leads to the most active metals as the relatively short reduction times at low temperatures leads to reduced sintering of the metal particles and hence higher reactivity. Fujita, et aL(62) have recently shown that lithium naphthalide in tqluepe can be prepared by sonicating lithium, naphthalene, and N, N, N, N-tetramethylethylene-diamine (TMEDA) in toluene. This allows reductions of metal salts in hydrocarbon solvents. This proved to be especially beneficial with cadmium(49). An extension of this approach is to use the solid dilithium salt of the dianion of naphthalene. Use of this reducing agent in a hydrocarbon solvent is essential in the preparation of highly reactive uranium(54). This will be discussed in detail below. 

In the solid-state structure of dilithiated fluoranthene (235), generated from 234 in dimethoxyethane at room temperature by Bock and coworkers (Scheme 82), lithium-DME units are capping the naphthalene moiety from both sides of the plane alternatingly (compound 235 forms a coordination polymer in the solid state). The metallic lithium, used for the reaction, was activated by ultrasonic irradiation. Moreover, several structures of related polysodium compounds were also characterized in the solid state . 

Solutions of dipositive lanthanide cations have been obtained in liquid ammonia, ethanol, THF, acetonitrile and hexamethylphosphoramide. Ions stabilized, or for which there is evidence for stabilization, include Nd2+, Dy2+ and Tm2+ as well as Eu2+, Yb2+ and Sm2+. The non-hydroxylic solvents are best at stabilizing M2+ ions. Thus NdCl2(THF)2 has been reported from the reduction of NdCl3 in THF by Na(naphthalene),657 and corresponding reductions of MC13 (M = Eu, Yb or Sm) have also been achieved.658 Solutions of solvated MI2 (M = Sm or Yb) in THF may easily be made by the quantitative reaction of the metal with 1,2-diiodoethane, producing ethane. The solid THF adducts may be isolated.659... 

Among substances that are sublimed under vacuum are anthranilic acid, hydroxyanthraquinone, naphthalene, and fl-naphthoi. Pyrogallol and d-camphor distill from the liquid state but condense as solids. Several metals are purified by sublimation, for instance, magnesium at 600°C and 0.01-0.15 Torr. 

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... 

Organic substances such as methane, naphthalene, and sucrose, and inorganic substances such as iodine, sulfur trioxide, carbon dioxide, and ice are molecular solids. Salts such as sodium chloride, potassium nitrate, and magnesium sulfate have ionic bonding structures. All metal elements, such as copper, silver, and iron, have metallic bonds. Examples of covalent network solids are diamond, graphite, and silicon dioxide. 

Toxicants to which subjects are exposed in the environment or occupationally, particularly through inhalation, may be in several different physical forms. Gases are substances such as carbon monoxide in air that are normally in the gaseous state under ambient conditions of temperature and pressure. Vapors are gas-phase materials that can evaporate or sublime from liquids or solids. Benzene or naphthalene can exist in the vapor form. Dusts are respirable solid particles produced by grinding bulk solids, whereas fumes are solid particles from the condensation of vapors, often metals or metal oxides. Mists are liquid droplets. 

Alexander s Explosive Ctmpositions consisted of naphthalene(with one or more other solid hydrocarbons), K picrate and oxidizers such as KNO, or KCIO, in various proportions Rgf Daniel (1902), 8 Alexander s Primary Explosive consisted of amorphous phosphoms 83 nnd Pb(NOj), (or other oxidizdng metal salt) 1%... 

Sorption of Pd on resin containing imidazolylazo functional groups was applied prior to the determination of the metal with PAN in geological and medicinal samples [3]. Solid (naphthalene)-liquid extraction of the complex with PAN has been described [4]. 

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