Phosphine

The phosphine is the common noun of the phosphorus hydride (name IUPAC: phosphane ). It is about a colorless and flammable gas. Its point of boiling is of −88 °C with a atmospheric pressure. Pure phosphine is odorless, but “technical phosphine” has an extremely unpleasant odor evoking garlic or rotted fish, because of the presence of substituted phosphine and diphosphine (P₂H₄).

Its formula is PH₃. It can be the result of a salt of aluminum Phosphure or magnesium, for example, which would have reacted with a Acide or quite simply with water where it is hydrolized.

Example:

AlP+ 3:00 ₂O --> PH₃ + Al (OH) ₃

aluminum phosphide + water --> phosphine (gas) + aluminum hydroxide.

Use

Rodenticide used to kill out of the Mole S or other vermins.
Doping agent in the industry of the Semiconductor S.

destruction of the insects and the acarina in the stored food products (silos, boats etc)

Precautions

Salts of phosphide of aluminum and all other metals, must be placed in such way so that they do not have access to ambient moisture, water or an acid! The product can be applied only by companies and of the approved personnel and under the control of the services of the protection of the plants.

Structure and properties

3 molecule has trigonal pyramid, i.e. it has C_3v symmetry with jump lengths off 1.42Å and Bond angle S off 93.5°. The Dipole moment is 0.58 D, which increases with Substitution off Methyl group S in the series: CH₃PH₂, 1.10 D; (CH₃) ₂PH, 1.23 D; (CH₃) ₃P, 1.19 D. This contrasts with Ammonia, which has off dipole moment 1.47 D, which decreases with successive methyl substitutions. The low dipole moment and almost orthogonal jump angles lead to that conclusion in PH₃ the pH jumps are almost entirely pσ (P) - sσ (H) and the lone even contributes only has little to the orbital Molecular off S. The high positive chemical shift the P atom in even ³¹P NMR agreements with the conclusion that the lone electrons occupy the 3s orbital and so are closed to the P atom (Fluck, 1973). This electronic structure leads to has lack off Nucleophilicity and year inability to form Hydrogen jumps.

The aqueous solubility off PH₃ is slight; 0.22 ml off gas/ml toilets At saturation. Phosphine dissolve more readily in not-whodunnit solvents than in toilets. It acts ace neither year NOR acid has base in toilets. Proton exchange is via has Phosphonium (PH₄⁺) ion in acidic solutions and via PH₂^- At high pH, with equilibribium constant KB = 4 X 10^-28 and Kz = 41.6 X 10^-29. -->

History

Chemistry

. Industrially it edge Be made by the reaction off white Phosphorus with Hydroxide of sodium, producing sodium Hypophosphite ace has by-product. It edge Be made (ace described above) by the hydrolysis off has metal phosphide such ace Aluminum phosphide gold calcium phosphide. Pure samples off phosphine, free from P₂H₄, may Be prepared using the action off Potassium hydroxide one Phosphonium iodide (PH₄I).

Related to PH₃ is the class off compounds commonly called phosphines . Thesis are alkyl gold aryl derivative off phosphine, just derivative aces Amine S edge Be regarded ace off Ammonia. Common examples include Triphenylphosphine ((C₆H₅) ₃P) and BINAP, both used ace phosphine ligands in metal complexes such ace Wilkinson' S catalyst. Such phosphines are often present ace Co Catalyst S in reactions such ace the Sonogashira coupling.

Phosphine is often confused with Phosgene, (COCl₂) which has similar-sounding name goal contains No phosphorus. -->

Use as smoke-producing agent

See too

Made up organophosphorés

External bond

http://phosphine.com

References

E. Fluck, The chemistry off phosphine , Topics in Current Chemistry vol. 35,64 p, 1973.
A.D.F. Toy, The Chemistry off Phosphorus , Pergamon Near, Oxford, the U.K., 1973.
WHO (World Health Organization), Phosphine and selected metal phosphides , Environmental Health Criteria. Published under the joint sponsorship off UNEP, ILO and WHO, Geneva, vol. 73,100 p, 1988.

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