PCls Phosphorus chloride

Phosphorus chloride (PCl ) ClgPjCg) 858 Potassium bromide (133r) Br K (l) 436... 

At left, the P-NMR references of phosphorus chlorides are depicted in order of decreasing coordination number of phosphorus. However, the coordination number is not expected to be the only ordering principle, as PCI/ would fall outside the range of PCl and the phosphonium salts are seen to resonate significantly upheld from PCI/. 

Chlorinated Fatty Acids. Chlorination of carboxylic acids is much more difficult because the contribution or the carbonyl group toward proton removal is offset by the electron donation effect from the hydroxyl group. This hindrance is obviated by reaction with the acid chloride or anhydride. Chlorination is normally accomplished hy use of n catalyst, such as phosphorus trichloride. Monochloroacelic acid is an important industrial chemical. Dichloro- and trichloroacetic acids can he produced by further chlorination, although the latter can be produced convenienlly by nitric acid oxidation of chloral. Higher chlorinalcd tally acids can be produced by treatment or the hydroxy carboxylic acid or ester with HCI ur PCL ... 

Naming becomes more difficult if the molecular complexity of a compound changes when it is fused or vaporized. Aluminum chloride is an ionic solid but vaporizes to dimeric molecules the solid is then aluminum trichloride whereas the vapor is dialuminum hexachloride. Similar considerations hold also for FeCl3, P2O5, and a number of additional compounds. Likewise, phosphorus(V) chloride is an appropriate name for PCI5 in the vapor state, but an ideal system of nomenclature should find some way of indicating that the solid consists of equal quantities of PCl and PClJf ions. It is a little difficult to decide just how much information about the structure of a compound must be included in its name before this name is to be considered adequate. 

The question of whether the phosphonitrilic chlorides have cyclic or linear structures has been frequently discussed in the literature. The structural evidence will be considered in Section lY, where it will be seen that the cyclic formulation is established beyond doubt for the trimer and tetramer, and is highly probable for the higher soluble polymers it will meanwhile be assumed for all compounds of formula (PNX2) . For reasons considered in Section II, C the petrol-insoluble fraction (PNCUln PCls is believed to consist of a mixture of linear polymers. The two series are related, in that the linear compounds of low molecular weight are intermediates in the formation of the cyclics by the ammonolysis of phosphorus pentachloride. 

A further method for the synthesis of cyclic compounds in the phosphinic acid series, and investigated within the last decade, is the clearly not unrelated cheletropic reaction which takes place between alka-1,3-dienes and phosphenium salts. The latter are based on dicoordinate phosphorus, [R R P ], the commonly encountered counter ion being the tetrachloroaluminate anion. Such salts are obtained in situ through the interaction of AICI3 and a hosphorus(III) chloride R R PCl, for which R = Cl, R = R2N, or R = R =... 

GaCl2 Gallium (II) chloride, 4 111 GaCla Gallium (III) chloride, 1 26 GaCls-PCls Gallium (III) chloride, compound with phosphorus (V) chloride, 7 81... 

Other phosphorus compounds, e.g. PBrs, mixtures of PBrs and Br2 or PCls/Ck and phenyltetra-chlorophosphorane (PhPCU) have been used to convert amides to imidoyl halides. The formation of imidoyl halides proceeds under mild conditions by action of triphenylphosphine/CCU or triphenylphos-phine dihalides on secondary amides or ketoximes. The work-up procedure can be facilitated by use of polymer-supported triphenylphosphine/CCU. By the action of POCI3, phenyl- or methyl-phos-phonic acid dichloride on aminocarboxylic acid thiol esters in the presence of triethylamine the imidoyl chlorides (205 equation 114) are form in moderate to good yields. The mechanism of this reaction has not been established. The methylene dialkylchlorophosphorane (206 equation 115) allows the conversion of secondary aromatic amides to imidoyl chlorides under very mild conditions. ... 

Phosphorus pentachloride-sodium azide lithium chloride PCl -NaNglLiCl... 

The mechanism of the reaction between FaB,NH3 and PCls, whose products include [a3P=N=PQ3]+[BCl4], involves bond formation between nitrogen and phosphorus via elimination of hydrogen chloride to... 

The pentachloride (Powell, Clark, and Wells, J, Chem, Soc. 1942, 642) and pentabromide (PoweD and Clark, Nature, 146, 971 [1940]) of phosphorus have been the subject of crystal structure investigations which have shown them to be ionic in the solid state. The ions are PCU and PCl for the chloride and PBr4 and Br for the bromide. This fact does not mean that they are not covalent in the gaseous state, nor does it imply that PFs is not pentacovalent in all three states. The boiling point for the fluoride is far below the boiling points of the chloride and bromide. If the fluoride were ionic, its boiling point would be higher. 

Hexachlorocyclotriphosphazene (NPCl2)3 was synthesized by the method of Saito (10). That is, (NPC a was prepared by the reaction of 500 g of phosphorus pentachloride PCls and 200 g of ammonium chloride NH4CI using 1500 mL of tetrachloroethane or chlorobenzene. Pure trimer was obtained by repeated fractional crystallization from light petroleum ether. 

Phosphorus oxide chloride (s. also under CgH NRs, C H N, and PCl ) Replacement of alkoxy groups by chlorine... 

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