Phosphides, Metallic metals

Phosphides. Compounds of phosphoms containing the more electropositive elements are generally called phosphides. A large number of binary phosphides as well as many ternary mixed-metal phosphides, metal phosphide nitrides, etc, are known. Some binary phosphides, such as those of nickel, exhibit a variety of stoichiometries (Ni P, Ni P2, Nq2P5, Ni2P, Ni P, NiP, NiP2, NiP ), whereas others, such as aluminum, form only one (AlP). Metalloids such as B and Si also form phosphides. 

The extension of this approach to artificial leaves based on titanates, niobates, tantalates, metal nitrides and phosphides, metal sulfides, and other transition metal oxides appears possible and useful in order to enhance the photocatalytic efficiency. In addition, the construction of multicomponent systems such as Ti02-CdS or MoS2-CdSe for overall water splitting could also lead to further improvements. This... 

The types of molecules considered in this work are those that have structural or chemical features that are manifestly different than are those of their more common oxidation state counterparts. Because of the breadth of this subject, selected examples are presented to illustrate typical behavior. The properties of the types of compounds containing the elements in more typical oxidation states may be found in the Inorganic and Organometallic sections describing each element or gronp and will not be discussed in this article. Similarly, minerals, metal phosphides, metal carbides, and compounds where the oxidation state of the element is low based on formal electron counting techniques (as in some catenated Catenation group 14 compounds), but that do not result in unusual chemistry, are not included. 

Some Lewis acids such as titanium trichloride and phosphorus pentachloride Metal phosphides such as aluminum phosphide or magnesium phosphide Metal hydrides Among them, an interesting classification can be proposed regarding the nature of the products issued from the decomposition by water ... 

Reaction with Phosphorus Nucleophiles. The ethyleneknine ring can be opened using phosphines (91) or alkaU metal phosphides (92) ... 

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... 

Phosphorus—Hydrogen Bond. A hydrogen bound to phosphoms has Httie acidic or hydric character. Most of the reactions the bond undergoes are those of a reducing agent. P—H bonds are formed by hydrolysis of active metal phosphides or phosphoms haUdes, by the rearrangement of P—O—H or P—S—H linkages, or by the hydrolysis of P—P bonds (6,17). 

In general, compounds having an active phosphoms—metal linkage react with alkyl haUdes. Such compounds include alkaU or alkaline-earth phosphides or phosphine derivatives, eg, Na P, PH2Na, XMgPR2, or... 

Some phosphides, such as titanium phosphide [12037-65-9] TiP, can be prepared bypassing phosphine over the metal or its haUde. Reaction of phosphine with heavy metal salt solutions often yields phosphines that may contain unsubstituted hydrogens. Phosphides may also be prepared by reducing phosphoms-containing salts with hydrogen, carbon, etc, at high temperatures, the main example of which is the by-product formation of ferrophosphoms in the electric furnace process for elemental phosphoms. Phosphoms-rich phosphides such as vanadium diphosphide [12037-77-3] may be converted to lower phosphides, eg, vanadium phosphide [12066-53-4] by thermal treatment. 

The alkah metal phosphides of formula M P and the alkaline-earth phosphides of formula M2P2 contain the P anion. Calcium diphosphide [81103-86-8] CaP2, contains P reaction with water Hberates diphosphine and maintains the P—P linkage. 

Phosphides of the less electropositive metals and the metalloids may be considered more as metal—phosphoms alloys. These are thermally stable... 

Copper and tin phosphides are used as deoxidants in the production of the respective metals, to increase the tensile strength and corrosion resistance in phosphor bronze [12767-50-9] and as components of brazing solders (see Solders and brazing alloys). Phosphor bronze is an alloy of copper and 1.25—11 wt % tin. As tin may be completely oxidized in a copper alloy in the form of stannic oxide, 0.03—0.35 wt % phosphoms is added to deoxidize the alloy. Phosphor copper [12643-19-5] is prepared by the addition of phosphoms to molten copper. Phosphor tin [66579-64-4] 2.5—3 wt % P, is made for the deoxidation of bronzes and German silver. 

Metal phosphides can be employed to direct the action of alkyl hahdes more toward primary and secondary phosphines. 

Products are contaminated with more highly alkylated compounds, but less so than without the active metal. The phosphide can be generated from a Grignard or organolithium reagent. 

The phosphido complex, Th(PPP)4 [143329-04-0], where PPP = P(CH2CH2P(CH2)2)2) has been prepared and fully characterized (35) and represents the first actinide complex containing exclusively metal—phosphoms bonds. The x-ray stmctural analysis indicated 3-3-electron donor phosphides and 1-1-electron phosphide, suggesting that the complex is formally 22-electron. Similar to the amido system, this phosphido compound is also reactive toward insertion reactions, especially with CO, which undergoes a double insertion (35,36). 

Titanium Phosphides. The titanium phosphides (154) include Ti P [12037-66-0], Ti P, and TiP (163). Titanium monophosphide [12037-65-9] TiP, can be prepared by beating phosphine with titanium tetrachloride or titanium sponge. Alternatively, titanium metal may be heated with phosphoms ia a sealed tube. The gray metallic TiP is slightly phosphoms-deficient (TiPQ has a density of 408(0) kg/m, and displays considerable... 

Phosphides. Zirconium forms several phosphides ZrP [39318-19-9] 2 [ 12037-80-8] and ZrP g [12066-61 -4]-, they are part of the Zr—P phase diagram (137). The solubiUty of phosphoms in zirconium metal is low, ca 50 ppm, and at higher concentrations it collects as separate globules at the metal grain boundaries. Analysis indicates that this material is Zr P. 

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 ... 

The most general preparative route to phosphides (Faraday s method) is to heat the metal with the appropriate amount of red P at high temperature in an inert atmosphere or an evacuated sealed tube ... 

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