Lithium diphenylphosphide contains lithium and the
organophosphorus anion with the formula (C
6H
5)
2PLi. It is an air-sensitive solid that is used in the preparation of diphenylphosphino compounds. As an ether complex, the lithium salt is dark red.
Synthesis and reactions
The lithium, sodium, and potassium salts are prepared by reduction of
chlorodiphenylphosphine
Chlorodiphenylphosphine is an organophosphorus compound with the formula (C6H5)2PCl, abbreviated Ph2PCl. It is a colourless oily liquid with a pungent odor that is often described as being garlic-like and detectable even in the ppb range. It is u ...
,
triphenylphosphine
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists a ...
,
or
tetraphenyldiphosphine
Tetraphenyldiphosphine is the organophosphorus compound with the formula Ph2sub>2, where Ph = phenyl (C6H5). It is a white, air-sensitive solid that dissolves in nonpolar solvents. It is a centrosymmetric molecule with a P-P bond of 2.2592 Å.
...
with alkali metals (M):
:(C
6H
5)
2PCl + 2 M → (C
6H
5)
2PM + MCl
:(C
6H
5)
3P + 2 M → (C
6H
5)
2PM + MC
6H
5
:(C
6H
5)
4P
2 + 2 M → 2 (C
6H
5)
2PM
They can also be obtained by deprotonation of
diphenylphosphine
Diphenylphosphine, also known as diphenylphosphane, is an organophosphorus compound with the formula (C6H5)2PH. This foul-smelling, colorless liquid is easily oxidized in air. It is a precursor to organophosphorus ligands for use as catalysts.
Syn ...
.
With water, the salts convert to
diphenylphosphine
Diphenylphosphine, also known as diphenylphosphane, is an organophosphorus compound with the formula (C6H5)2PH. This foul-smelling, colorless liquid is easily oxidized in air. It is a precursor to organophosphorus ligands for use as catalysts.
Syn ...
:
[
:(C6H5)2PLi + H2O → (C6H5)2PH + LiOH
With ]halocarbon
Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms (fluorine, chlorine, bromine or iodine – ) resulting in the formation of organofluorine compounds, organochlori ...
s, the salts react to give tertiary phosphines:
:(C6H5)2PM + RX → (C6H5)2PR + MX
When treated with metal halides, lithium diphenylphosphide gives transition metal phosphido complexes A transition metal phosphido complex is a coordination complex containing a phosphido ligand (R2P, where R = H, organic substituent). With two lone pairs on phosphorus, the phosphido anion (R2P−) is comparable to an amido anion (R2N−), except t ...
.
Structure
Although treated as salts, alkali diphenylphosphides are highly aggregated in solution. They adopt polymeric structures as solids.
Related compounds
* Sodium diphenylphosphide (CAS RN
A CAS Registry Number (also referred to as CAS RN or informally CAS Number) is a unique identifier, unique identification number assigned by the Chemical Abstracts Service (CAS), US to every chemical substance described in the open scientific li ...
4376-01-6)
* Potassium diphenylphosphide (CAS RN 15475-27-1)
References
{{Lithium compounds
Lithium salts
Organolithium compounds
Phenyl compounds
Phosphines