The Metallic Compounds

Specific metals properties electric conductibility, glossiness, malleability and ductility, suggest that their internal structure should be different to the other solids. 

The simplest structure model of the metals corresponds to an ensemble of positive ions, surroimded by mobile electrons (the so-called electronic gases), the total electrons number being equal with the sum of the positive charges of the ions placed in the nodes of the lattice. 

The metallic lattices ions are not identical to the common cations from the combinations of relative elements. 

For electrons to be able to fieely move in crystal is necessary that the nodal particles ( metallic atoms ) to present free orbital where the electrons from neighboring particles ean pass through. 

The representation of nodal particles by ions actually is related with this possibility of electrons migration from an atom to other. 

---

Depending upon the metallic compound used, different metallic phthalocyanine derivatives are obtained, e.g. when copper chloride is used copper phthalocyanine (Monastral Fast Blue B) is obtained. 

Many methods for the conversion of acid copolymers to ionomers have been described by Du Pont (27,28). The chemistry involved is simple when cations such as sodium or potassium are involved, but conditions must be controlled to obtain uniform products. Solutions of sodium hydroxide or methoxide can be fed to the acid copolymer melt, using a high shear device such as a two-roU mill to achieve uniformity. AH volatile by-products are easily removed during the conversion, which is mn at about 150°C. A continuous process has been described, using two extmders, the first designed to plasticate the feed polymer and mix it rapidly with the metal compound, eg, zinc oxide, at 160°C (28). Acetic acid is pumped into the melt to function as an activator. Volatiles are removed in an extraction-extmder which follows the reactor-extmder, and the anhydrous melt emerges through a die-plate as strands which are cut into pellets. 

In a simple pyrometaHurgical reduction, the reduciag agent, R, combines with the nonmetal, X, ia the metallic compound, MX, according to a substitution reaction of the foUowiag type ... 

Precipitation is affected by pH, solubiUty product of the precipitant, ionic strength and temperature of the aqueous stream, and the presence of metal complexes. For each metal precipitant, there is an optimum pH where its solubiUty is lowest and hence, the highest removals may be achieved. When an aqueous stream contains various metals, the precipitation process caimot be optimized for each metal, sometimes making it difficult to achieve effluent targets for each. SolubiUty products depend on the form of the metal compound and ate lowest for metal sulfides, reflecting the relative insolubiUty of these compounds. For example, the solubiUty product for lead sulfide [1314-87-0] is on the order of compared to 10 for lead carbonate. Metal... 

The carbon residue is a measure of the carbon compounds left in a fuel after the volatile components have vaporized. Two different carbon residue tests are used, one for light distillates, and one for heavier fuels. For the light fuels, 90% of the fuel is vaporized, and the carbon residue is found in the remaining 10%. For heavier fuels, since the carbon residue is large, 100% of the sample can be used. These tests give a rough approximation of the tendency to form carbon deposits in the combustion system. The metallic compounds present in the ash are related to the corrosion properties of the fuel. 

For metal compounds, the calculation of the reportable concentration and treatment efficiency is based on the weight ot the parent metal, not on the weight of the metal compounds Metals are not destroyed, only physically removed or chemically converted from one form into another. The treatment efficiency reported represents only physical removal of the parent metal from the wastestream, not the percent chemical conversion of the metal compound. If a listed treatment method converts but does not remove a metal (e.g., chromium reduction), the method must be reported, but the treatment efficiency must be reported as zero. 

All sequential treatment steps must be indicated for the metal compound categories reported even if the treatment method does not affect the particular metal. For example, ionic exchange must be reported as a treatment method for lead, zinc, chromium, and selenium compounds, oven though the method affects only the selenium compound. 

Section 313 requires emissions reporting on the chemical categories listed below, in addition to the specific chemicals listed above. The metal compounds listed below, unless otherwise specified, are defined as including any unique chemical substance that contains the named metal (i.e., antimony, copper, etc.) as part of that chemical s structure. 

SWCNT is synthesized by almost the same method as that- for the synthesis of MWCNT. Remarkable difference lies in the fact that metallic catalyst is indispensable to the synthesis of fullerenes. The metal compounds used as the catalyst are listed in Table 2 [8]. 

If the metallic compound in the ore can be selectively leached by acid or base without dissolving much of the remaining ore, then the energy requirement is only about 10 J/kg. Examples are leaching of oxide ores of copper, zinc, or uranium with sulfuric acid. 

The electrolytic processing of concentrated ore to form the metal depends on the specific chemical properties of the metallic compound. To produce aluminum about 2 to 6 percent of purified aluminum oxide is dissolved in ciyolite (sodium alumi-no-fliioride, Na AlF ) at about 960°C. The reduction of the alumina occurs at a carbon (graphite) anode ... 

As discussed in Chapter 2, nickel, vanadium, and sodium are the metal compounds usually present in the FCC feedstock. These metals deposit on the catalyst, thus poisoning the catalyst active sites. Some of the options available to refiners for reducing the effect of metals on catalyst activity are as follows ... 

However, they can also be prepared by metal exchange from alkali-metal phthalocyanines. If proton donors like hydrochloric acid, water or methanol are added to the reaction mixture of a freshly prepared alkali-metal phthalocyanine, metal-free phthalocyanines (PcH2) are formed (see Section 2.1.4.1,). If, on the other hand, the appropriate metal salt is added to a solution of an alkali-metal phthalocyanine, the product is the metalated compound (PcM) (see Section 2.1.6.). 

If lanthanide salts (e.g., Yb(OAc)3 H20) are used as the metal compound, hexadecasub-stituted bis(phthalocyanines) can be prepared starting from 2,3,9,10,16.17,23,24-octa-substituted metal-free phthalocyanines.201... 

A number of mixed metalloxanes, R MOSnRrX (M = Hg, Tl, Si, Ge, or Pb), have similarly been synthesized from the stannoxanes (R2SnO) and the metal compounds R MX (250), and the borostannoxanes B(OSnRs)3 and (R0)2B0SnR20SnR20B(0R)2 have also been characterized (251, 252). 

Our approach, to achieve a high dispersion of the metal compound while the oxide network is formed, is to employ metal complexes of the type LnM[X(CH2)3Si(OR)3]y in the sol-gel process [2]. The metal ions then cannot aggregate because of complexation, and the metal complexes cannot leach because they are linked to the oxidic support. These complexes are formed in situ on reaction of silanes of the type X(CH2)nSi(OR)3 with suitable metal salts. 

In addition to the reactions just described using molten pipHSCN, several reactions have been carried out at low temperature by sonicating mixtures of metal salts and pipHSCN (House, 1998). The use of ultrasound results in products of higher purity than when the molten salt is used. This is probably due to the fact that some of the products are not very stable at the temperature of the molten salt (100 °C) and mixtures result under those conditions. In carrying out the reactions, the amine hydrothiocyanate and the metal compound were suspended in dodecane and pulsed ultrasound was applied. The fol-... 

The acid component of a hydrocracking catalyst can be an amorphous oxide, e.g., a silica-alumina ora zeolite, eg., USY. This component usually serves as a support for the metal compound responsible for the hydrogenation function. The metal compound can be a noble metal, e.g., Pt or Pd, or a mixture of sulfides, e.g., of Ni/Mo, NiAV, or Co/Mo. The relative amounts of the respective compounds have to be thoroughly balanced to achieve an optimum performance. 

Table 1 lists some of the metal compounds employed and the results obtained when attempts were made to cast films of the resulting metal ion filled polyimide derived from BTDA + m,m -DABP. Brittle films were produced in most cases regardless of whether the added metal ion was hydrated or anhydrous. The relatively low viscosities of the resulting polyamic acid-metal ion solutions no doubt accounted for this. Addition of AlCl3 6H20 or any simple aluminium salt to the polyamic acid produced immediately a rubbery material that could not be cast into a film. 

Two different mechanisms have been proposed for the ROP of (di)lactones depending on the nature of the organometalhc derivatives. Metal halides, oxides, and carboxylates would act as Lewis acid catalysts in an ROP actually initiated with a hydroxyl-containing compound, such as water, alcohol, or co-hydroxy acid the later would result more hkely from the in-situ hydrolysis of the (di)lac-tone [11]. Polymerization is assumed to proceed through an insertion mechanism, the details of which depends on the metal compound (Scheme la). The most frequently encountered Lewis acid catalyst is undoubtedly the stannous 2-ethylhexanoate, currently referred to as stannous octoate (Sn(Oct)2). On the other hand, when metal alkoxides containing free p-, d-, or f- orbitals of a favo-... 

Considerable uncertainty still exists about the state of the metal compounds in the solutions "It s dark behind the pick"... 

The solutions of the metal compounds M3X7 can be used (a) for a study of redox-reactions under mild conditions, and (b) to serve as aducts for cation exchange reactions. Thus KaaPv reacts with phi PCl or phi AsCl accompanied by quantitative precipitation of KaCl, to give solutions of salts without metal cations. The least soluble materials which crystallize out of these solutions are the compounds (phi P)2Pie or (ph As)2Pie They contain the new polyanion Pie (Figure 5)> which is formed in the solution by a complex redox reaction (J 8). 

Borides. The new compound TmCrB. has been prepared and shown to be isostructural with YCrB. The conditions for preparing the metallic compound Cr7BC4 from the elements have been investigated. ... 

Reactions of the metallated compounds with electrophiles are discussed in Section 8.01.7.16. 

The MelDAS technology is a modified incineration process in which high temperatures destroy organic contaminants in soil and concentrate metals into fly ash. Details of the metals immobilization process can vary based on the specific application, but the essential steps are to combine the toxic-metal containing material with the appropriate amount of sorbent, to form this mixture into pellets or briquets placing the metal compounds into intimate contact with the sorbent, and to heat treat the pellets causing a reaction to form nonleachable metal compounds. The MelDAS process requires a sorbent. 

When it goes about metal carbonyls or about metals of the second or even third transition row, the DFT methods seem to be able to do the job quite decently. However, turning to compounds of the first transition row metals with open d-shells raises many problems. Intuitively distinction in behavior of two types of the metal compounds is clear to any chemist. In a row of... 

La2Cu04. The metallic compounds (a) are hypothetical materials without disproportionation or magnetic interactions which cause band splitting (b) when the o band is half filled. Both p-type (c) and n-type (d) conductors are shown. 

Jhe reaction mechanism of the various metal complexes clearly have much in common. The recently recognized insertion reaction appears to be a particularly good example of a reaction which is general among the metal compounds. In the following discussion I intend to point out the generality of the insertion reaction with examples from the literature and from our own wrork. The most complete series of substantiated insertion reactions involves the organocobalt carbonyl complexes, and these reactions will form the nucleus of the discussion. 

Che et al. also prepared Pt/Ru nanoparticle-filled carbon tubes with a diameter of 200 nm (40). They impregnated carbon-deposited film with a mixture of aqueous solutions of HiPtClf, and RuCI3. After drying in air, the metal compounds in the pores were reduced by H2 flowing at 580°C for 3 h. Then the underlying alumina was dissolved away in HF solution. TEM observation of this sample revealed the presence of Pt/Ru nanoparticles (about 1.6 nm) dispersed on the inner wall of the tubes. 

Note that in Lavoisier s account of these relationships, the metal is simple and the calx is compound, just the reverse of the phlogistic view, which had the calx simple, and the metal compound. This interpretation derives from his model of the gaseous state as a combination oPsome solid or fluid body with the inflammable principle. Lavoisier clearly summarized his... 

---