Metal/chlorine displacement

Nitrogen Displaces the Metal Phosphorus Displaces the Metal Oxygen Displaces the Metal Sulfur Displaces the Metal Fluorine Displaces the Metal Chlorine Displaces the Metal Bromine Displaces the Metal Iodine Displaces the Metal... 

Non-metals also vary in reactivity. In, for example, Group VII of the periodic table (the halogens), chlorine is more reactive than iodine. If you pass chlorine gas.into potassium iodide solution, the solution goes brown because the chlorine displaces iodine from the potassium iodide. Iodine in KI has an oxidation number of — 1 and this rises to 0 in the elemental iodine, so iodine has been oxidised. The opposite occurs with chlorine. 

Many nonmetals displace less active nonmetals from combination with a metal or other cation. For example, when chlorine is bubbled through a solution containing bromide ions (derived from a soluble ionic salt such as sodium bromide, NaBr), chlorine displaces bromide ions to form elemental bromine and chloride ions (as aqueous sodium chloride) ... 

A variety of other nucleophiles have been used for the metal-catalyzed displacement of chlorine in nonactivated chloroarenes, including arylthiolate [191-193] and iodide [194, 195] anions, primary and secondary amines [196, 197], tertiary phosphines [198,199], and aminophosphines [200]. All these reactions are catalyzed by either preformed or generated in situ Ni(0) complexes. Very recently, however, Reddy and Tanaka [201] and Koie et al. [202] reported the arylation of secondary amines with chlorobenzene and other chloroarenes, catalyzed by palladium complexes containing bulky, electron-rich phosphines,... 

Electrolytic processes. Because of the positive oxidation potential for plutonium metal to displace hydrogen from aqueous solution, as shown in Table 9.7, nonaqueous solutions such as fused salts must be used for the electrodeposition of plutonium metal. One process involves the electrolysis of a molten equimolar mixture of LiCl-KCl containing 30 w/o FuQs. The melt is contained in a MgO-TiOi crucible heated to 950 C, with an anode through which chlorine gas can be introduced... 

Anhydrous hydrogen fluoride (as distinct from an aqueous solution of hydrofluoric acid) does not attack silica or glass. It reacts with metals to give fluorides, for example with heated iron the anhydrous iron(II) fluoride is formed the same product is obtained by displacement of chlorine from iron(II) chloride ... 

Replacement of Labile Chlorines. When PVC is manufactured, competing reactions to the normal head-to-tail free-radical polymerization can sometimes take place. These side reactions are few ia number yet their presence ia the finished resin can be devastating. These abnormal stmctures have weakened carbon—chlorine bonds and are more susceptible to certain displacement reactions than are the normal PVC carbon—chlorine bonds. Carboxylate and mercaptide salts of certain metals, particularly organotin, zinc, cadmium, and antimony, attack these labile chlorine sites and replace them with a more thermally stable C—O or C—S bound ligand. These electrophilic metal centers can readily coordinate with the electronegative polarized chlorine atoms found at sites similar to stmctures (3—6). 

Displacement of activated chlorine atoms also proceeds with certain types of organic compounds, but only in the presence of Lewis acid catalysts. Particular examples include epoxides, polyhydric alcohols, trialkylphosphites (12), and P-aminocrotonates (13). These additives are commonly used in conjunction with metallic stabilizers to provide complete, high performance, commercial stabilizer packages. 

Phosphites. Tertiary phosphites are also commonly used and are particularly effective ia most mixed metal stabilizers at a use level of 0.25—1.0 phr. They can take part ia a number of different reactions duting PVC processing they can react with HCl, displace activated chlorine atoms on the polymer, provide antioxidant functionaHty, and coordinate with the metals to alter the Lewis acidity of the chloride salts. Typical examples of phosphites are triphenyl phosphite [101 -02-0], diphenyl decyl phosphite [3287-06-7], tridecyl phosphite [2929-86-4], and polyphosphites made by reaction of PCl with polyols and capping alcohols. The phosphites are often included in commercial stabilizer packages. 

The iodides of the alkaU metals and those of the heavier alkaline earths are resistant to oxygen on heating, but most others can be roasted to oxide in air and oxygen. The vapors of the most volatile iodides, such as those of aluminum and titanium(II) actually bum in air. The iodides resemble the sulfides in this respect, with the important difference that the iodine is volatilized, not as an oxide, but as the free element, which can be recovered as such. Chlorine and bromine readily displace iodine from the iodides, converting them to the corresponding chlorides and bromides. 

Tiichloiomethanesulfenyl chloiide can be reduced to thiophosgene by metals in the presence of acid and by various other reducing agents. The sulfur-bonded chlorine of trichloromethanesulfenyl chloride is most easily displaced by nucleophilic reagents, but under some conditions, the carbon-bound chlorines are also reactive (54). 

Metal carboxyiates have been considered as nucleophilic agents capable of removing aHyUc chlorine and thereby affording stabilization (143). Typical PVC stabilizers, eg, tin, lead, or cadmium esters, actually promote the degradation of VDC polymers. The metal cations in these compounds are much too acidic to be used with VDC polymers. An effective carboxylate stabilizer must contain a metal cation sufftcientiy acidic to interact with aHyUc chlorine and to facihtate its displacement by the carboxylate anion, but at the same time not acidic enough to strip chlorine from the polymer main chain (144). 

Gold ores can be concentrated by froth flotation, the resulting concentrate being roasted at 600-800°C to oxidize off sulphur and arsenic as their oxides. The product is extracted with cyanide under oxidizing conditions (using either peroxide or air itself) before displacement with powdered zinc. More reactive metals (silver etc.) can be removed by chlorination of molten gold. 

Sodium, a metal, replaces iron, another metal. Fluorine, a nonmetal, replaces chlorine, another nonmetal. (In some high-temperature reactions, a nonmetal can displace a relatively inactive metal from its compounds.) The formulas for F2, NaCl, NaF, and Cl2 are written on the basis of the rules of chemical bonding (Chap. 5). 

A greatly improved experimental procedure for the synthesis of thieno[2,3-d]-1,2,3-thiadiazole caiboxylates 68 was reported by Stanetty et al. and involved diazotisation of aminothiophene derivatives 67 <99JHC761>. In these systems, substituents could be introduced into the 5-position by nucleophilic displacement of a chlorine atom or by metallation of the unsubstituted compound (68 R = H) and subsequent electrophilic quenching <99JPR391>. 

It is easy to argue that the behavior of the [Co en2 Cl2]+ isomers is not surprising. The correlation of aquation rates of complexes of the type, [Co en2 A Cl]n+ with the electron displacement properties of the nonparticipating ligand, A, has led to the belief that ligands able to donate a second pair of electrons to the metal can thereby stabilize the 5-coordinate intermediate and hence promote a unimolecular reaction (2, 18, 24). Chlorine is such a ligand, Cl—Co- -Cl, and the essentially first-order kinetic form could be used as evidence for a unimolecular mechanism, once the ion association pre-equilibrium effects for the displacement of chloride under the electron-displacing influence of the other chlorine atom have been taken into account. 

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