Reactions with metal compounds

The results of earlier investigations are described in Phosphor C, 1965, pp. 44/8. Reactions with metal compounds, in particular of Fe and Cu , which are used for the oxidative removal of PH3 from mixtures of gases, are described in Section 1.3.1.5.4, pp. 224/5. Reactions leading to the formation of films or layers of phosphorus compounds on different substrates are described in Section 1.3.1.6, pp. 293/308. 

Excess PH3 and GaCl3 (at ambient temperature) and GaBr3 (with gentle heating) form 1 1 adducts in reactions of the neat compounds [9,10]. The same products are also obtained as precipitates from benzene solutions. The reaction of PH3 with Gal3 did not yield a pure product [10]. The reaction of PH3 in H2 with gaseous InCl evaporated at 600 C starts to yield crystalline InP at 350 C and proceeds efficiently at a reaction temperature of 400 C [11,12]. The yield of InP from the reactions of PH3 with InCl3 or InBr is considerably lower [11]. 

Transition Metal Compounds. The reaction of excess PH3 with TaFg suspended in anhydrous HF results in the gradual dissolution of the solid with formation of PH4TaFg [15]. 

The oxidation of adsorbed PH3 by M0O3 on an AI2O3 support starts at 300 C and is accompanied by the consumption of isolated OH species on the solid surface. The complete conversion to the products H2 and an adsorbed species containing the HPO moiety requires 350 C. The reaction can be used for the batchwise catalytic oxidation of PH3 added O2 regenerates M0O3 and oxidizes the adsorbed HPO groups with formation of (HO)xPO which can be removed by heating in vacuum [33]. 

Dehydrated Mn3[Co(CN)g]2 xH20 absorbs PH3 with formation of Mn3[Co(CN)6]2 xPH3 the value of X was not given [17]. The reaction of excess PH3, paraformaldehyde, and (C2H5)3N with the cage complex [Co(sen)p with sen = 4,4, 4 -ethylidynetris(3-azabutan-1-amine) in acetonitrile at ambient temperature yields a mixture of the phospha-capped cage complex [Co(Mephosphasar)p (Mephosphasar=8-methyl-3,6,10,13,16,19,1 -hexaazaphosphabicyclo-[6.6.6]icosane) and its phosphane oxide derivative [16]. 

Vanadium pentoxide heated in a stream of nitrogen trifluoride for 12 h at 400°C gives N0[V0F4] nearly quantitatively and small amounts of VOF3, NO, and NO2 [1]  

V205 + 3NF3- 2V0F3 + 3FN0 V0F3+FN0- N0[V0F4] 

Only about 60% of chromium(lll) oxide reacted with nitrogen trifluoride at 430°C to give Crp3 and a relatively large amount of FNO (10% of the gaseous products), NO, and NO2 [1]  

Cr203 + 3NF3 2CrF3-h3FN0 Cr203 + 6 FNO2CrF3-h 3 NO + 3 NO2 

Nitrogen trifluoride and chromium(VI) oxide do not react up to 200°C, the decomposition temperature of the latter [1]. 

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Chapter I discusses some general questions relevant to the chemistry of alkanes and especially their reactions with metal compounds. Transformations of saturated hydrocarbons in the absence of metal derivatives and in the presence of solid metal and metal oxide surfaces are described in Chapters n and 111 (Figure 1). Since these reactions are not the main topic of the monograph their consideration here is far from comprehensiveness but the knowledge of such processes is very important for understanding the peculiarities and mechanisms of the reactions with metal complexes. Chapters IV-X are the main chapters of this book because they describe the activation of hydrocarbons in the presence of... 

In cyclometalation reactions with metal compounds instead of the metal atoms discussed above, ligands such as hetero atom groups (e.g., bipyridines, phosphines, and carboxylates), unsaturated groups (e.g., aryl, allyl, Cp and Cp ), carbonyl groups, halogen atoms (F, Cl, Br, Cl), etc., also act as metal activators. 

CHR) , formed, e g. from the reaction of diazomethane and alcohols or hydroxylamine derivatives in the presence of boron compounds or with metal compounds. Poly-methylene is formally the same as polyethene and the properties of the various polymers depend upon the degree of polymerization and the stereochemistry. 

Reactions with Orgunometullic Compounds of the Main Group Metals via Transmetallation... 

Small amounts of specially functionalized monomers are often copolymerized with acryUc monomers in order to modify or improve the properties of the polymer. These functional monomers can bring about improvements either directiy or by providing sites for further reaction with metal ions, cross-linkers, or other compounds and resins. Table 9 Hsts some of the more common functional monomers used in the preparation of acryUc copolymers. 

Reaction with Inorganic Compounds. Most metals and alloys react with aqueous hydrochloric acid via... 

Phosphoms shows a range of oxidation states from —3 to +5 by virtue of its electronic configuration. Elemental P is oxidized easily by nonmetals such as oxygen, sulfur, and halides to form compounds such as 2 5 2 5 reduced upon reaction with metals to generate phosphides. The... 

Because of the time and expense involved, biological assays are used primarily for research purposes. The first chemical method for assaying L-ascorbic acid was the titration with 2,6-dichlorophenolindophenol solution (76). This method is not appHcable in the presence of a variety of interfering substances, eg, reduced metal ions, sulfites, tannins, or colored dyes. This 2,6-dichlorophenolindophenol method and other chemical and physiochemical methods are based on the reducing character of L-ascorbic acid (77). Colorimetric reactions with metal ions as weU as other redox systems, eg, potassium hexacyanoferrate(III), methylene blue, chloramine, etc, have been used for the assay, but they are unspecific because of interferences from a large number of reducing substances contained in foods and natural products (78). These methods have been used extensively in fish research (79). A specific photometric method for the assay of vitamin C in biological samples is based on the oxidation of ascorbic acid to dehydroascorbic acid with 2,4-dinitrophenylhydrazine (80). In the microfluorometric method, ascorbic acid is oxidized to dehydroascorbic acid in the presence of charcoal. The oxidized form is reacted with o-phenylenediamine to produce a fluorescent compound that is detected with an excitation maximum of ca 350 nm and an emission maximum of ca 430 nm (81). 

The precious metals possess much higher specific catalytic activity than do the base metals. In addition, base metal catalysts sinter upon exposure to the exhaust gas temperatures found in engine exhaust, thereby losing the catalytic performance needed for low temperature operation. Also, the base metals deactivate because of reactions with sulfur compounds at the low temperature end of auto exhaust. As a result, a base metal automobile exhaust... 

Solutions of alkali metals in liquid ammonia have been developed as versatile reducing agents which effect reactions with organic compounds that are otherwise difficult or impossible/ Aromatic systems are reduced smoothly to cyclic mono- or di-olefins and alkynes are reduced stereospecifically to frani-alkenes (in contrast to Pd/H2 which gives cA-alkenes). 

The factors in carboaromatic nucleophilic displacements summarized in this section are likely to be characteristic of heteroaromatic reactions and can be used to rationalize the behavior of azine derivatives. The effect of hydrogen bonding and of complexing with metal compounds in providing various degrees of electrophilic catalysis (cf. Section II, C) would be expected to be more extensive in heteroaromatics. 

Oppenauer oxidation of the enol ether (34) affords the corresponding 17 ketone (37) (the enol ether is stable to the basic oxidation conditions). This ketone affords the corresponding 17a-ethynyl compound on reaction with metal acetylides. Hydrolysis of the enol ether under mild conditions leads directly... 

Formation from Other Group-IIIB Compounds 6.5.3.4. by Reaction with Metal Halides... 

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