Diphosphane, or diphosphine, is an
inorganic compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemis ...
with the chemical formula P
2H
4. This colourless liquid is one of several binary phosphorus hydrides. It is the impurity that typically causes samples of
phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
to ignite in air.
Properties, preparation, reactions
Diphosphane adopts the
gauche conformation (like
hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
, less symmetrical than shown in the image) with a P−P distance of 2.219
angstrom
The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.m ...
s. It is nonbasic, unstable at room temperature, and
spontaneously flammable in air. It is only poorly soluble in water but dissolves in organic solvents. Its
1H NMR spectrum consists of 32 lines resulting from an A
2XX'A'
2 splitting system.
Diphosphane is produced by the hydrolysis of
calcium monophosphide, which can be described as the Ca
2+ derivative of . According to an optimized procedure, hydrolysis of 400 g of CaP at −30 °C gives about 20 g of product, slightly contaminated with
phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
.
Reaction of diphosphane with
butyllithium affords a variety of condensed polyphosphine compounds.
Organic diphosphanes
A variety of organic derivatives of diphosphane are known. These species are prepared by reductive coupling, e.g.
tetraphenyldiphosphine from
chlorodiphenylphosphine:
:2 ClPPh
2 + 2 Na → Ph
2P−PPh
2 + 2 NaCl
The methyl compound P
2Me
4 is prepared by the reduction of Me
2P(S)−P(S)Me
2, which is produced by methylation of
thiophosphoryl chloride with methylmagnesium bromide.
See also
*
Pnictogen hydride Pnictogen hydrides or hydrogen pnictides are binary compounds of hydrogen with pnictogen ( or ; from grc, πνῑ́γω "to choke" and -gen, "generator") atoms (elements of group 15: nitrogen, phosphorus, arsenic, antimony, and bismuth) cova ...
References
Phosphorus hydrides
Foul-smelling chemicals
{{Hydrides by group