Phosphorus and Aluminium

The chemistry of compounds of phosphorus with aluminium, gallium or indium has been explored to a very much less extent than that of phosphorus with boron. The simple monophosphides of all these elements are isostructural and contain only M-P linkages (Chapter 8.5). Inorganic structures based on corner-linked [AIO4] and [PO4] tetrahedra are dealt with in Chapter 5.7. 

Phosphide anions of composition (9.127a) have been shown to be present in the salt CsgAljP while long chains are present in NasAlP2 (9.127b) [4]. Aluminium phosphide, AlP, is dealt with in Chapter 8.3. 

Most known compounds with Al-P linkages are one of two types (9.128). Those of the type contain a formal donor bond like their boron analogues (9.4). 

The simple addition complexes of the aluminium trihalides are formally analogous to those of the boron trihalides. Phosphine and phosphorus trihalides form addition compounds of the type X3P-ADC3, where X = H or halogen and X = halogen (9.129). 

Thermally stable H3Al-P Bu3 can be compared with thermally unstable H3AI-PH3. 

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Solid-state NMR spectroscopy was used for studying the formation of cubic mesoporous aluminophosphate thin films and powders. The analysis of the initial gel, the as-deposited materials and the thermally-treated materials elucidated the changes in the coordination of phosphorus and aluminium atoms and thus revealed how the framework formation and condensation proceeds. The consolidation process in thin films was different than the process in powders. Most probably this could be attributed to the effect of glass substrate. 

P and 27A1 MAS NMR spectra of aluminophosphate powders and of samples scratched from films were recorded on 600 MHz Varian NMR system equipped with a Varian 3.2 mm MAS probe. Fifty two-faced films deposited on glass slides were needed to obtain sufficient amount of material for NMR measurements. Larmor frequencies for phosphorus and aluminium at 14.1 T are 242.89 and 156.35 MHz, respectively. 

Carbon disulphide is an excellent solvent for fats and resins, - it is employed technically for the extraction of vegetable fats and oils and for removing fats from wool. It dissolves rubber, camphor and other organic substances, as well as iodine, sulphur, phosphorus and aluminium bromide.7... 

Aluminium Phosphide was made by a reaction between red phosphorus and aluminium powder.13,14 It formed yellow crystals. These materials when heated in an electric furnace yielded A13P and A1P, which were crystalline substances of a metallic appearance.16,16 A13Pj was obtained when phosphorus and aluminium were heated to a white heat in a current of hydrogen. 

When the nucleus under study has poor abundance, such as for carbon-13, the cross polarization technique is used. This uses a complex pulse sequence to transfer the polarization from a nucleus with high abundance (normally hydrogen, but phosphorus and aluminium are also used) to the second nucleus, enhancing its signal. 

Clarkson. E.M., Luck, V.A., Hynson, W.V., et al. (1972). The effect of aluminium hydroxide on calcium, phosphorus and aluminium balances, the serum parathyroid hormone concentration and the aluminium content of bone in patients with chronic renal failure. Clin. Sci., 43, 519-531. 

In each of the examples given so far each element has achieved a noble gas configuration as a result of electron sharing. There are. however, many examples of stable covalent compounds in which noble gas configurations are not achieved, or are exceeded. In the compounds of aluminium, phosphorus and sulphur, shown below, the central atoms have 6. 10 and 12 electrons respectively involved in bondinc... 

Electroless nickel deposition may then be carried out directly onto steel, aluminium, nickel or cobalt surfaces. Surfaces of copper, brass, bronze, chromium or titanium are not catalytic for deposition of nickel-phosphorus and the reaction must be initiated by one of the following operations ... 

Two contrasting conclusions have been reported in the reactions of lithium aluminium hydride in THF with phosphine oxides and phosphine sulphides respectively. The secondary oxide, phenyl-a-phenylethylphos-phine oxide (42), has been found to be racemized very rapidly by lithium aluminium hydride, and this observation casts some doubt on earlier reports of the preparation of optically active secondary oxides by reduction of menthyl phosphinates with this reagent. A similar study of the treatment of (/ )-(+ )-methyl-n-propylphenylphosphine sulphide (43) with lithium aluminium hydride has revealed no racemization. These results have been rationalized on the basis of the preferred site of attack of hydride on the complexed intermediate (44), which, in the case of phosphine oxides (X = O), is at phosphorus, and in the case of the sulphides (X = S), is at sulphur. Such behaviour is comparable to that observed during the reduction of phosphine oxides and sulphides with hexachlorodisilane. ... 

In a study of dental silicate cements, Kent, Fletcher Wilson (1970) used electron probe analysis to study the fully set material. Their method of sample preparation varied slightly from the general one described above, in that they embedded their set cement in epoxy resin, polished the surface to flatness, and then coated it with a 2-nm carbon layer to provide electrical conductivity. They analysed the various areas of the cement for calcium, silicon, aluminium and phosphorus, and found that the cement comprised a matrix containing phosphorus, aluminium and calcium, but not silicon. The aluminosilicate glass was assumed to develop into a gel which was relatively depleted in calcium. 

Contact with boron, silicon, red phosphorus, sulfur, or arsenic, antimony or bismuth usually causes incandescence [1]. Solid potassium or molten sodium explode with the pentafluoride, and aluminium foil ignites on prolonged contact [2], Molybdenum and tungsten incandesce when warmed [3],... 

Cabrera et al. [95] determined total dissolved and suspended phosphorus in natural waters by a method involving digestion with hydrogen peroxide and sulphuric acid, errors may be caused by adsorption of phosphorus on hydrous iron and aluminium oxides formed during neutralization prior to filtration. It is proposed that this can be prevented by adding extra sulphuric acid after neutralization, to dissolve such oxides and release the adsorbed phosphorus into solution. 

This may be the reason why silicon is essential, namely that it keeps aluminium in a non-toxic form as aluminium silicate. While silicon is required as a trace element in most animals, in plants, particularly grasses, and in many unicellular organisms, such as diatoms4, it is a major structural element. The importance of phosphorus and sulfur is obvious, the latter often associated with iron in an important family of proteins that contains iron-sulfur clusters. 

The aim was to assess the feasibility of substitution with less hazardous flame retardants. They selected red phosphorus, ammonium polyphosphate and aluminium trihydroxide as the least environmentally problematic alternatives. Red phosphorus can technically be used in a variety of polymers to meet even the toughest fire safety standards, although it may network forall applications. ... 

Abstract The term Lewis acid catalysts generally refers to metal salts like aluminium chloride, titanium chloride and zinc chloride. Their application in asymmetric catalysis can be achieved by the addition of enantiopure ligands to these salts. However, not only metal centers can function as Lewis acids. Compounds containing carbenium, silyl or phosphonium cations display Lewis acid catalytic activity. In addition, hypervalent compounds based on phosphorus and silicon, inherit Lewis acidity. Furthermore, ionic liquids, organic salts with a melting point below 100 °C, have revealed the ability to catalyze a range of reactions either in substoichiometric amount or, if used as the reaction medium, in stoichiometric or even larger quantities. The ionic liquids can often be efficiently recovered. The catalytic activity of the ionic liquid is explained by the Lewis acidic nature of then-cations. This review covers the survey of known classes of metal-free Lewis acids and their application in catalysis. 

The methods for the preparation of bromotrimethylsilane include the treatment of hexamethyldisiloxane with bromine reagents such as phosphorus tribromide,1,2 2,2,2-tribromo-l, 3,2 /5-benzodioxaphosphole (catechyl phosphorus tribromide),2 and aluminium tribromide,3 the yields being in the range from 73 to 87%. A further method4 shows that bromotrimethylsilane can be obtained from aminosilanes and hydrobromic acid, but the yield (55%) is lower than in the former methods. Other methods involve the use of expensive reagents, such as hexamethyldisilane, l,4-bis(trimethylsilyl)-2, 5-cyclohexadiene, and 1,4-dihydro-l, 4-bis(trimethylsilyl)naphthalene.5 Finally, some alternative procedures have been developed for its in situ preparation.5... 

Phosphorus dissolves in arsenic trichloride on warming without reaction and is deposited on cooling.8 If the mixture is heated in the presence of aluminium chloride at 130° to 150° C. for 40 minutes, a brownish-red compound of composition A1As3C13 results,9 from which, however, aluminium chloride can readily be removed by water or ammonia, leaving a residue of finely divided black arsenic. If the compound is heated to 190° C. in the absence of air, it turns black as arsenic trichloride and aluminium chloride distil off and a bright grey mixture of arsenic and arsenide remains. It has been suggested that the arsenic is co-ordinatively bound, and that the compound may be /Ass... 

The reducing agents usually employed are phosphorus and hydriodic acid, or the zinc-copper or the aluminium-mercury couple. The couples have the advantage of readily yielding a pure gas, and are of wide application. 

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