Phosphorus Binary Compounds

Other Phosphorus—Nitrogen Compounds. Of the binary phosphoms—nitrogen compounds, only triphosphoms pentanitride [12136-91 -3] 3 5 been obtained in a pure state. It can be prepared by treatment of P S q with ammonia and subsequent heating of the intermediate... 

Phosphides are binary compounds containing anionic phosphorus (P ). Heavy metal, alkali, and alkaline earth metal phosphides exist but few of them are commercially important. Phosphides hydrolyze to the flammable and toxic gas phosphine (PH3). The hydrolysis reaction of aluminum phosphide is given below ... 

PCI3 Phosphorus is not a metal, so use the guidelines for binary compounds phosphorus trichloride. 

Most nonmetallic elements will react with the group IA and IIA metals to give binary compounds. Heating the metals with nitrogen or phosphorus gives nitrides and phosphides of the metals. 

Although the products in these equations are written as if they were simple ionic binary compounds, this is not always the case. For example, some nonmetals form clusters containing several atoms arranged in polyhedral structures. One such species is the P73- cluster, which has six phosphorus atoms at the vertices of a trigonal prism with the seventh occupying a position above a triangular face... 

Sulfur also forms binary compounds by reacting with phosphorus and halogens. 

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. 

Lanthanum combines with nitrogen, carbon, sulfur and phosphorus at elevated temperatures, forming binary salts. Also, with metalloid elements such as boron, silicon, selenium, and arsenic, similar reactions occur at high temperatures forming similar binary compounds. 

The metal reacts with nitrogen, phosphorus, sulfur and selenium at elevated temperatures forming their binary compounds ... 

Rhenium combines with phosphorus, arsenic, silicon, selenium, and tellurium at elevated temperatures forming binary compounds. The metal, however, is stable in hydrogen and nitrogen at high temperatures. 

The metal reacts with halogens above 200°C forming its trihalides. It combines with nitrogen above 1,000°C producing a nitride, YN. It combines at elevated temperatures forming binary compounds with most nonmetals and some metalloid elements such as hydrogen, sulfur, carbon, phosphorus, silicon, and selenium. 

The Union of Two Elementary Substances.— The most obvious way in which to prepare a binary compound is by the union of the two constituent elements, though in many cases this is not the most practicable way. Sometimes, the elements are first prepared in pure form and are then combined in other cases, the preparation of the elements and their union is effected in one operation, as in the manufacture of calcium carbide and carborundum. In general, the more dissimilar the two elements the more likely they are to combine readily, but elements of the same general kind sometimes combine with ease, as is the case with chlorine and iodine, sulfur and phosphorus, or sodium and lead. 

Thus the hydride is a very efficient carrier of hydrogen. Upon heating, calcium reacts with boron, sulfur, carbon, and phosphorus to form the corresponding binary compounds and with carbon dioxide to form calcium carbide [75-20-7], CaC2, and calcium oxide [1305-78-8], CaO. 

Other elements with which iron forms binary compounds, especially at higher temperatures, are boron, carbon, nitrogen, silicon, and phosphorus, l.ike FeO, these compounds often depart slightly or even considerably from daltonide composition, frequently being interstitial compounds, and in higher elements of groups VB and VIB, merging into the interstitial compound-solid solution picture which iron exhibits with the transition metals. 

As a metal, Np has a relatively low melting point ( -640°C), is very dense (20.45 g/cnr), and is ductile. The alpha form reacts with hydrogen, carbon, oxygen, sulfur, the halogens, and phosphorus to yield a number of binary compounds. 

Since 1965 we have found an unexpected number of binary phosphorus hydrogen compounds in addition to the well-known hydrides PH and 2H4 (Table I). These phosphanes have been detected in the hydrolysis products of calcium phosphide or in the thermolysis products of 2H4 mass spectroscopy. Only the compounds... 

Phosphorus forms various compounds with all elements except Sb, Bi, and the inert gases for the binary compounds. The stereochemistry and bonding of phosphorus are very varied. Some typical coordination geometries are summarized in Table 15.4.1 and illustrated in Fig. 15.4.2. Many of these compounds will be discussed below. 

Many binary compounds of non-metals with non-metals are known, but such compounds usually can exist only out of contact with water. For example, phosphorus trichloride is completely hydrolyzed by water. Write the equation for this reaction, and treating it as a metathesis, conclude which element in the phosphorus trichloride is to be regarded as the positive constituent. 

To indicate that a binary compound is made up of two non-metals, a prefix is usually added to both non-metals in the compound. This prefix indicates the number of atoms of each element in one molecule or formula unit of the compound. For example, P205 is named diphosphorus pen-toxide. Alternatively, the Stock System may be used, and P205 can be named phosphorus (V) oxide. AsBr3 is named phosphorus tribromide. 

The alkali metals and alkaline earth metals are reactive toward most nonmetallic elements. Accordingly, they react with nitrogen, phosphorus, and arsenic to give binary compounds, but only those of nitrogen and phosphorus will be considered here. The reactions occur when the two elements are heated together as shown in the following equations ... 

Although the products are written as simple ionic binary compounds, it is known that complex materials containing anions that consist of polyhedral species containing the nonmetal are also produced. For example, a P73- cluster is known, which has six of the phosphorus atoms arranged in a trigonal prism with the seventh occupying a position above the triangular face on one end of the prism. 

Binary compounds of the metals and the less electronegative non-metals with phosphorus are made by methods which recall those employed in the preparation of nitrides. The most important of these methods may be classified as follows —... 

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