Phosphine (PH3) Properties (25 Facts You Should Know)

Phosphine is a hazardous phosphorous hydride, formed naturally by the anaerobic decay of organic compounds containing phosphorous. It is classed as pnictogen hydride.

Phosphine is flammable (pyrophoric) and it burns with the luminous flame. It is highly toxic compound for the respiratory system and at the concentration of 50ppm it becomes injurious to health. There are several uses of phosphine as it is used as a fumigant, polymerization initiator.

Lavoisier first obtained phosphine in 1783 in the laboratory. Let us see various properties of phosphine like the odor, viscosity, covalent radius, acidic and basic nature in detail.

Phosphine IUPAC name

The IUPAC name of PH₃ is phosphane.

Phosphine chemical formula

The chemical formula of phosphine is PH₃.

Phosphine CAS number

The CAS number of phosphine is 7803-51-2.

Phosphine ChemSpider ID

The chemSpider ID of phosphine is 22814.

Phosphine chemical classification

• Phosphine contains Phosphorous which belongs to the main group element.

• Phosphine contains phosphorous and is a p-block element and belongs to the Nitrogen family. Hydrogen belongs to the s-block element in the periodic table.

Phosphine molar mass

The molar mass of phosphine is 33.99 g/mol.

Phosphine colour

Phosphine is a colourless gas.

Phosphine viscosity

The viscosity of phosphine is 1.1*10^-5. Viscosity is the measure of the resistance of a fluid to deformation.

Phosphine molar density

The molar density of phosphine is 1.379 g/L.

Phosphine melting point

The melting point of phosphine is -132.8^oC.

Phosphine boiling point

The boiling point of phosphine is -87.7^oC.

Phosphine state at room temperature

Phosphine is gaseous at room temperature and is highly flammable in air.

Phosphine covalent bond

Phosphine has a covalent bond with dipole moment of 0.58 D. This increases with the substitution of methyl groups.

Phosphine covalent radius

The covalent radius of P-H bond is 1.42 Angstrom. It is the measure of the distance between two atoms.

Phosphine electron configurations

Electronic configurations is arrangements of electrons in the shell. Let us see the electronic configuration of Phosphine.

In Phosphine Hydrogen has only one electron so its electronic configuration is 1s¹. In phosphorous the electronic configuration is 1s²2s²2p⁶3s²3p⁶.

Phosphine oxidation state

The oxidation state of phosphorous in Phosphine is -3.

Phosphine acidity/alkaline

Phosphine is amphoteric in nature which means it neither basic nor acidic in nature. It is neutral in nature. Amophoteric species are those which acts as both acids and bases.

Is phosphine odourless?

Phosphine is odourless as pure compound. Commercially it has fishy or garlic smell.

Is phosphine paramagnetic?

Paramagnetic species are those which contains an unpaired electrons. Let us see the Para magnetism of phosphine.

Phosphine is diamagnetic species because of the presence of paired electrons in the orbitals of phosphorous. In the presence of external magnetic field para magnetic species are easily attracted whereas the diamagnetic species are not easily attracted.

Phosphine hydrates

Depending on the conditions Phosphine reacts with the water in different proportions to give mixtures of orthophosphoric acid and phosphorous acid.

Phosphine crystal structure

Phosphine crystal structure is trigonal pyramidal in shape.

Phosphine polarity and conductivity

• Phosphine is a non-polar compound because of the presence of non-polar P-H bonds.

• Phosphine forms covalent bonds with other compounds hence it is non-conductive.

Phosphine reaction with acid

Phosphine reacts with acids to give phosphonium ions (PH₄⁺). Phosphine has lone pair of electrons. On reaction with an acid which is a H⁺ donor PH₄⁺ is formed. The reaction with an acid is an irreversible reaction.

PH₃ + H⁺—->PH₄+

Phosphine reaction with base

Phosphine reacts with the base to give phosphanide (PH₄^–) ion and this reaction is reversible in nature.

PH₃+ OH^–—->PH_4^–

Phosphine reaction with oxide

Phosphine reacts with the oxygen to give phosphine oxide. It has the chemical formula OPX₃. It is tetrahedral in shape. Phosphine oxides are also generated as a by-product in many reaction. For example- In Wittig reactions Phosphine oxides are obtained as a by product.

R₃P+1/2 O₂ —-> R₃PO

Phosphine reaction with metal

Phosphine reacts with metal to give the metal phosphine complex which is also a coordination complex. Metal phosphine complex are also used in homogenous catalysis. For example Wilkinson’s catalyst, Grubbs catalyst.

RhCl₃(H₂O)₃ + 4 PR₃ —-> RhCl(PR₃)₃ + OPPh₃ + 2 HCl + 2 H₂O

Conclusion

In this article we have discussed about the various properties of the phosphine like the melting point, boiling points, magnetism and various chemical properties like reaction with the metals, reaction with the non-metals and many more.