Phosphorous pentafluoride

Critical compressibility factor 0.282 Latent heat of fusion (-93.8°C) 12.104 kJ/gmole 

No occupational exposure limit have been established by OSHA, NIOSH, or ACGIH 

Poisoning may effect the skeleton, kidneys, and central nervous system. Respiratory tract irritation, coughing, choking, and bums of the mucous membranes can be expected. 

Pulmonary edema may develop immediately or after a latency of 5-72 hours. Additional symptoms include chest tightness, dyspnea, cyanosis, rapid pulse, and hypotension. Death can result from severe exposures. 

May react violently on contact with water. Reacts with organic materials and reducing chemicals. 

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Dalton, B. J. (1971), Nonrigid Molecule Effects on the Rovibronic Energy Levels and Spectra of Phosphorous Pentafluoride, J. Chem. Phys. 54,4745. de Shalit, A., and Talmi, 1. (1963), Nuclear Shell Theory, Academic Press, N.Y. 

In addition to rotation and inversion, there are other mechanisms by which conformational interconversion may occur. One of these, pseudorotation , is most easily seen in a molecule like phosphorous pentafluoride which adopts a trigonal bipyramidal equilibrium geometry with distinct equatorial and axial fluorines. 

Hartree-Fock 6-3IG calculations show that pseudorotation in phosphorous pentafluoride is a very low energy process (6 kcal/mol) and that the square-based pyramid structure is indeed a transition state. 

Pseudorotation. A mechanism for interconversion of equatorial and axial sites around trigonal bipyramidal centers, e.g., fluorines in phosphorous pentafluoride. 

Table 9. The effect of temperature on the composition of poly(4-methyl-l-pentene) using phosphorous pentafluoride coinitiator"...

Compounds containing 02 cation 340 are colorless with the exception of 02+PtF6, which is red due to the PtF6 ion. The compound 02+PF6 decomposes slowly at 80°C862 and rapidly at room temperature, giving oxygen, fluorine, and phosphorous pentafluoride. 18F tracer studies on 02+BF4 have led to the conclusion that the mechanism of the decomposition involves the equilibrium [Eq. (4.216)] followed by a bimolecular decomposition of 02F.863... 

In a recent article (59) Kops and Spanggaard report that m-7,9-dioxabicyclo[4,3,0]-nonane is transformed quantitatively into the cyclic dimer when treated with a catalytic amount of phosphorous pentafluoride or triethyloxonium hexachloroantimonate. From an NMR study the dimer was concluded to have the cis-anti-as structure. 

In toluene with phosphorous pentafluoride as initiator the polymerization was completely reversible with temperature change, leading to a mixture of monomer, cyclic dimer and polymer the ratio of which depended on the temperature. Polymerization starting with the dimer instead of monomer lead to the same equilibrium mixture. 

Methyl mercaptan Phosphorous pentafluoride Phosphorous trifluoride... 

Phosphorous Pentafluoride, PF5, mw 125.98, colorless gas, fr p —91.6°, bp —84.8°, d of gas 5.84g/liter sol in or reacts with.w, alcohols, ethers amines gas produces a fog in moist air not corrosive to dry metals or glass, The toxicity is same order as that of BFj. Phosphorous pentafluoride can be made by treating the chloride with.arsenic trifluoride, and by thermal decompn of hexafluorophos-phates the diazonium salts. PFS may be converted to PF5 by heating Cl alone, or with, calcium fluoride... 

Phosphorous pentafluoride was shown by Muetterties (23, to initiate polymerization of cyclic ethers to high-molecular-weight polymers. 

Polymerization of this cyclic monomer yields polymers that consists of strictly alternating oxymethylene and oxyethylene units [76]. the polymerization reaction can be induced by acidic catalysts, like sulfuric acid, boron trifluoride, p-toluenesulfonic, acid and phosphorous pentafluoride [76] ... 

S. Brownstein, J. Inorg. Nucl. Chem. 1973, 35, 3567-3574. Complex fluoroanions in solution—11. Reactions of boron trifluoride and phosphorous pentafluoride with group VB... 

Director or Indirect Gas Detection. In selecting a gas detector, it is important to note whether a detector responds to the target gas directly or indirectly. For example, in monitoring for phosphorous pentafluoride, an indirect gas detector might detect hydrogen fluoride (a by-product created when phosphorous pentafluoride comes in contact with moisture in the air). In order for this indirect gas detector to provide satisfactory protection, the proper environmental conditions, such as a sufficient humidity level, must exist in the monitored area.t Sometimes gas detectors are selected to monitor for the presence of a carrier gas used in conjunction with the actual target gas. Care must be taken withthis approach since carrier gas detection characteristics and limits relative to the target gas may not afford adequate protection. 

Fluorine magnetic resonance spectra have been studied for this compound and it has been shown that it is possible to detect the difference in structure between the apical and equatorial positions in trigonal bipyramids [ ]. However, for phosphorous pentafluoride it was found that the difference is too small to detect. When one of the fluorine atoms is removed and an alkyl group is substituted, it is then possible to see the influence that the two positions have. 

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