Tetraphenyldiphosphine

{{Chembox

| ImageFile = Ph4P2.svg

| ImageSize =

| ImageAlt =

| PIN = Tetraphenyldiphosphane

| OtherNames =

|Section1={{Chembox Identifiers

| CASNo = 1101-41-3

| PubChem = 70673

| EC_number = 214-155-9

| ChemSpiderID = 63839

| ChEMBL = 68039

| DTXSID = DTXSID60149141

| StdInChI=1S/C24H20P2/c1-5-13-21(14-6-1)25(22-15-7-2-8-16-22)26(23-17-9-3-10-18-23)24-19-11-4-12-20-24/h1-20H

| StdInChIKey = DAPZRBJQPPDZGH-UHFFFAOYSA-N

| SMILES = C1=CC=C(C=C1)P(C2=CC=CC=C2)P(C3=CC=CC=C3)C4=CC=CC=C4

}}

|Section2={{Chembox Properties

| C=24|H=20|P=2

| MolarMass =

| Appearance = white solid

| Density = 1.292 g/cm³

| MeltingPtC = 125

| BoilingPt =

| Solubility = }}

|Section3={{Chembox Hazards

| GHSPictograms = {{GHS02}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|250}}

| PPhrases = {{P-phrases|210|222|280|302+334|370+378|422}}

| MainHazards =

| FlashPt =

| AutoignitionPt = }}

}}

Tetraphenyldiphosphine is the organophosphorus compound with the formula [PPh₂]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.{{cite journal |last1=Tam |first1=Eric C. Y. |last2=Maynard |first2=Nicola A. |last3=Apperley |first3=David C. |last4=Smith |first4=J. David |last5=Coles |first5=Martyn P. |last6=Fulton |first6=J. Robin |title=Group 14 Metal Terminal Phosphides: Correlating Structure with ‖ J_MP ‖ |journal=Inorganic Chemistry |date=17 August 2012 |volume=51 |issue=17 |pages=9403–9415 |doi=10.1021/ic301208d|pmid=22900884 }}

Tetraphenyldiphosphine is produced by reductive coupling of chlorodiphenylphosphine...{{cite encyclopedia|encyclopedia=Encyclopedia of Reagents for Organic Synthesis|doi=10.1002/047084289x.rn00839|entry=Tetraphenyl­diphosphine|first1=Al|last1=Postigo|first2=Sebastian|last2=Barata}}

:2 Ph₂PCl + 2 Na → Ph₂P-PPh₂ + 2 NaCl

...or dehydrogenation of diphenylphosphine catalyzed by bis(triphenylphospine)nickel(II) bromide:{{cite journal|doi=10.1021/ol017238s|journal=Organic Letters|year=2002|volume=4|issue=5|p=762|title=Catalytic hydrophosphination of styrenes|first1=Mstislav O.|last1=Shulyupin|first2=Marina A.|last2=Kazankova|first3=Irina P.|last3=Beletskaya|orig-date=December 17, 2001|publisher=American Chemical Society}}

:2 Ph₂PH → Ph₂P-PPh₂ + H₂

The compound is used as a source of the Ph₂P⁻ group.{{cite journal|title=Zur Kenntnis der Organophosphorverbindungen, III. Umsetzungen mit Diphenylphosphin-natrium

|first1=Wilhelm |last1=Kuchen|first2=Hans|last2=Buchwald|journal=Chem. Ber.|volume=92|pages=227–231

|year=1959|doi=10.1002/cber.19590920126}}

:Ph₂P-PPh₂ + 2 Na → + 2 NaPPh₂

Alternatively, the compound can homolyze along the weak P–P bond, in which case the resulting radicals add to alkenes and alkynes.

Oxidation with oxygen or sulfur gives the corresponding diphosphine dioxide or disulfide.{{cite journal|doi=10.1021/ja00714a020|publisher=American Chemical Society|date=3 June 1970|title=Reactions of calcium carbide: Novel synthesis of tetraphenyl­diphosphine and diphenyl­phosphinic anhydride|orig-date=6 Oct 1969|volume=92|issue=11|journal=Journal of the American Chemical Society}}