Reactions with nonmetal compounds

The results of earlier investigations are described in Phosphor C, 1965, pp. 40/3. Oxidation reactions of PH3 with nonmetal compounds which can be used for the removal of small amounts of the compound, mainly from mixtures with other gases, are described in Section 1.3.1.5.4, pp. 222/33. Weakly bound complexes including a small number of PH3 adducts were reviewed in [1]. 

Halogen Compounds. Weakly hydrogen-bound van der Waals complexes of PH3 with hydrogen halides were generated from the diluted gases. The reactions were carried out either by pulsed-nozzle supersonic expansion with pulse-coupled microwave spectroscopic detection (MW) or by isolation in matrices at low temperature with identification by IR spectroscopy (IR). Experimentally observed complexes are H3P---HF (MW [2], IR [8]), H3P---HCI (MW [4], IR [3, 5]), and H3P---HBr (MW [6], see also [4]). 

The formation of H3P - (HX)2 in cocondensed samples in matrices was deduced for X = F [3, 5] and Cl [3] from IR bands which were absent immediately after condensation, but which grew strongly in intensity on annealing the samples. The energetics and the geometry of (HF)2 were computed in an ab initio MO calculation at the SCF/6-31G level [12]. 

The dissolution of PH3 in anhydrous HF leads to complete protonation [23]. The UV photolysis of PH3/HI mixtures in Xe matrices at 4.2 to 100 K yields PH4 via decomposition of HI into the atoms [103]. 

Matrix-isolated H3P - CIF was obtained by twin-jet deposition of the diluted reactants and identified by IR spectroscopy. Large shifts of the bands of the complex with respect to those of the isolated constituents indicate a quite strong bond between both reactants [24]. A complex of the molecules PH3 and CIF without a hydrogen bond was also predicted to be favored by the product of the reference electrostatic potentials [14]. 

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Reaction with Nonmetals. Bromine oxidi2es sulfur and a number of its compounds. 

Reactions of Pb(C2H5)4 with nonmetal compounds have been reviewed in [45, 80, 87]. References ... 

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... 

When a free element reacts with a compound of different elements, the free element will replace one of the elements in the compound if the free element is more reactive than the element it replaces. In general, a free metal will replace the metal in the compound, or a free nonmetal will replace the nonmetal in the compound. A new compound and a new free element are produced. As usual, the formulas of the products are written on the bases presented in Chap. 5. The formula of a product does not depend on the formula of the reacting element or compound. For example, consider the reactions... 

In substitution reactions, hydrogen in its compounds with nonmetals often acts like a metal hence, it is listed among the metals in Table 7.1. 

In substitution reactions with acids, metals that can form two different ions in their compounds generally form the one with the lower charge. For example, iron can form Fe2+ and Fe3+. In its reaction with HCI, FeCI2 is formed. In contrast, in combination with the free element, the higher-charged ion is often formed if sufficient nonmetal is available. 

Reacts with many metals to give hydrogen, sometimes violently. With non-metals pyrophoric hydrides may result. Frequently initiates explosive reactions between other substances. Violent reactions with many non-metal and some metal halides and oxyhalides, also with many organometallic compounds. Many metal nonmetal-lides produce toxic, flammable or pyrophoric gases on contact with diprotium monoxide. 

Metals react with nonmetals. These reactions are oxidation-reduction reactions. (See Chapters 4 and 18). Oxidation of the metal occurs in conjunction with reduction of the nonmetal. In most cases, only simple compounds will form. For example, oxygen, 02, reacts with nearly all metals to form oxides (compounds containing O2-). Exceptions are the reaction with sodium where sodium peroxide, Na202, forms and the reaction with potassium, rubidium, and cesium where the superoxides, K02, Rb02, and Cs02 form. 

The periodic table can give us many clues as to the type of reaction that is taking place. One general rule, covered in more detail in the Bonding chapter, is that nonmetals react with other nonmetals to form covalent compounds, and that metals react with nonmetals to... 

Iron reacts with nonmetals forming their binary compounds. It combines readily with halogens. Reaction is vigorous with chlorine at moderate temperature. With oxygen, it readily forms iron oxides at moderate temperatures. In a finely divided state, the metal is pyrophoric. Iron combines partially with nitrogen only at elevated temperatures. It reacts with carbon, sulfur, phosphorus, arsenic, and silicon at elevated temperatures in the absence of air, forming their binary compounds. 

The important compounds of nitrogen with hydrogen are ammonia, hydrazine, and hy dr azoic acid, the parent of the shock-sensitive azides. Phosphine forms neutral solutions in water reaction of nonmetal halides with water—hydrolysis—produces oxoacids but no change in oxidation number. 

Nonaqueous electrolyte solutions can be reduced at negative electrodes, because of an extremely low electrode potential of lithium intercalated carbon material. The reduction products have been identified with various kinds of analytical methods. Table 3 shows several products that detected by in situ or ex situ spectroscopic analyses [16-29]. Most of products are organic compounds derived from solvents used for nonaqueous electrolytes. In some cases, LiF is observed as a reduction product. It is produced from a direct reduction of anions or chemical reactions of HF on anode materials. Here, HF is sometimes present as a contaminant in nonaqueous solutions containing nonmetal fluorides. Such HF would be produced due to instability of anions. A direct reduction of anions with anode materials is a possible scheme for formation of LiF, but anode materials are usually covered with a surface film that prevents a direct contact of anode materials with nonaqueous electrolytes. Therefore, LiF formation is due to chemical reactions with HF [19]. Where does HF come from Originally, there is no HF in nonaqueous electrolyte solutions. HF can be produced by decomposition of fluorides. For example, HF can be formed in nonaqueous electrolyte solutions by decomposition of PF6 ions through the reactions with H20 [19,30]. 

The reaction of a free element with a compound of two (or more) other elements may result in the free element displacing one of the elements originally in the compound. A free metal can generally displace a less active metal in a compound a free nonmetal can generally displace a less active nonmetal in a compound ... 

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