Metal phosphides applications

In this review, we present a selection of studies from our own laboratory, intended to introduce a solid-state chemist to both the practical and theoretical considerations that need to be taken into account in XPS measurements of solids with substantial covalent character. Metal phosphides, arsenides, and antimonides represent such a category of solids where the bonding retains some polarity that notions of electron counting derived from the Zintl concept still prove helpful in providing a frame of reference for comparing charge distributions. We also describe the applications of XAS to complementary studies of the electronic structure of these materials. 

The method of greatest applicability is the reaction of alkali metal phosphides with dihalo-alkanes, -alkenes, etc. (equation 4). Generally this reaction proceeds well and in high yield excess dihaloalkane should be avoided as this leads to the production of phosphonium salts which can contaminate the product. 

The numerous applications of phosphines include (1) synthetic reagents, (2) ligands in metallo-phosphorus compounds, (3) catalysts, (4) metal deposition agents, (5) electron-rich compounds. Metallophosphines (metal phosphides) types MPR2 and M2PR (M=Li, Na, K) are especially useful in synthesis (Chapter 8.8) (Table 6.8). 

The majority of metal phosphides have a metal arsenide analogue which they usually resanble in properties and structure (Table 8.2). Metal phosphides, arsenides and nitrides not infrequently exhibit properties similar to those of metal carbides, silicides and germanides. Some metal phosphides are very useful semiconductors, while others shew superconduction or a variety of magnetic properties. Light-emitting diodes (LEDs) and nanostructured materials are other modem applications (Chapter 12.19). 

Applications discovered for metal phosphides (Chapter 8) are extremely diverse (Figure 12.32). At the present time, the industrial applications of greatest importance are those in the fields of metallurgy and electronics. The latter are dealt with in Section 12.20. 

The fields of application of metal phosphides can be divided into the following ... 

Potential Application of Metal Oligophosphanides as Precursors in the Preparation of Metal Phosphides... 

Metal phosphides have been extensively studied for many applications, for example, corrosion-resistant materials [94], catalysts for hydrodesulfurisation and hydrodenitrogenation of petroleum fuels [95-100] and oxygen barriers in capacitors [101]. In addition, applications associated with the magnetic properties of these compounds have been also studied in depth [102-105]. 

Some of the chapters of this book are more focused on the synthetic developments in phosphorus containing materials. This is the case of Chap. 2, which reviews the aspects concerning phosphine acetylenic macrocycles and cages, and Chap. 12, which deals with the important field of P-based cryptands, cyclophanes, and corands. Chapter 4 addresses the potential applications of metal complexes containing anionic phosphoms chains for the synthesis of metal phosphides, whereas the synthesis of P-compounds via the metal catalysed addition of P-H bonds to unsaturated organic molecules is thoroughly reviewed in Chap. 8. 

Soft, silver white metal that melts in the hand (29.8 °C) and remains liquid up to 2204 °C (difference 2174 °C, suitable for special thermometers). Gallium is quite widespread, but always in small amounts in admixtures. Its "career" took off with the advent of semiconductors. Ga arsenide and Ga phosphide, which are preferential to silicon in some applications, have extensive uses in microchips, diodes, lasers, and microwaves. The element is found in every mobile phone and computer. Ga nitride (GaN) is used in UV LEDs (ultraviolet light-emitting diodes). In this manner, a curiosity was transformed into a high-tech speciality. 

Metal-recovery operations, phosgene in, 18 810-811. See also Metals recycling Metal reductions hydrazine, 13 569 to liquid metal, 16 141-146 Metal refining, 16 149-151 barium application, 3 349 limestone in, 15 38-39 Metal removal, in electrochemical machining, 9 593-595 Metal-rich phosphides, 19 59... 

Which is the best catalyst for accelerating the reaction depends on the nature of the working materials. For the reaction of hydrogen or oxygen in potassium hydroxide solution, nickel or silver is suitable for carbonaceous fuels as well as for the reaction of oxygen in acid electrolytes platinum metals were up to the middle 60s, the only known catalysts. Precious metals are ruled out by price for wide application in fuel cells, and the search for cheaper catalysts has been actively pursued in many research laboratories. Many classes of inorganic substances (carbides, nitrides, oxides, sulfides, phosphides, etc.) have been investigated and, in particular, several chelates. 

Indium has many industrial uses for electronics and electrical applications [9] indium metal in germanium transistors indium alloys for soldering and glass sealing of electronic devices indium antimonide, arsenide, and phosphide in infrared detectors and semiconductor applications indium-silver alloys for brazing and electroplated indium metal for electrical connectors. For underground telephone cables, indium has been used to plate copper-to-aluminum connectors. About 2-5 tons of indium alloyed with silver and cadmium has been used annually in nuclear reactor control rods. 

Another solid electrolyte that has recently found fairly wide application in thermochemical e.m.f. work is calcium fluoride which is reversible to fluoride ions. Galvanic cells employing this electrolyte have been used to obtain thermochemical data for the Gibbs energy of formation of metal fluorides, carbides, borides, and phosphides at temperatures of 875 to 1120 K. Typical examples are the cells ... 

In addition to the coumarins, certain indanediones, ureas, and other organics find application as rodenticides. Phosphine formed by the slow hydrolysis of metal (usually aluminium and zinc) phosphides continued to be employed for rodent control despite the obvious toxicological hazard. In many third world countries, rodents are a major problem, limiting both the harvest and the storage of grains, as well as being an important public health hazard. 

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