Phosphorus pentabromide structure

However, phosphorus pentachloride in the solid state has an ionic lattice built up of (PC ) and (PClg)" ions and these ions are believed to exist in certain solvents. Thus under these conditions the maximum covalency is reached with chlorine. In phosphorus pentabromide, PBrj, the solid has the structure [PBr4] [Br] . 

Describe the hybridization state of phosphorus in phosphorus pentabromide (PBrs). Answer The Lewis structure of PBrs is... 

Phosphorus pentabromide and various trialkylphosphine dihalides should be examined for mode of reactivity with Grignard and lithium reagents. The rare pentavalent phosphorus compounds substituted with organofunctional groups appear to offer interesting structural considerations. The preliminary x-ray diagram of pentaphenylphosphorus was published recently (193). ... 

It is possible to decide between formula (1) on one hand and formulas (2) and (3) on the other from a consideration of the methods of formation of the two dibromoethanes. One of these compounds is formed when acetaldehyde is treated with phosphorus pentabromide. The structure of acetaldehyde has been shown by methods independent of this reaction to be represented by the following formula —... 

Although phosphorus pentabromide exists in the vapor phase as PBrs molecules, in the solid phase the substance is ionic and has the structure [PBr4 ]Br . What is the expected geometry of PBr4 Describe the bonding to phosphorus in PBr4. ... 

In the gas phase, phosphorus pentachloride and pentabromide have the trigonal bipyramid structure (D3h symmetry),... 

In the conversion of acetaldehyde into dibromoethane the simplest interpretation of the reaction leads to the view that the oxygen which it contains is replaced by two of the bromine atoms of the pentabromide, which is thereby converted into phosphorus oxybromide, POBrs its structure is, accordingly, that represented in formula (4) above. The dibromoethane formed in this way is not the one which results from the addition of bromine to ethylene this latter compound must, as a result, have the structure represented by formula (5) above, since formulas (4) and (5) represent all the possible configurations of a compound of the composition C2H4Br2. These facts exclude the possibility that ethylene has the structure represented by formula (1). 

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. 

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