Hexaphenylcarbodiphosphorane

Hexaphenylcarbodiphosphorane
Names
	Preferred IUPAC name Methanediylidenebis(triphenyl-λ5-phosphane)
	Other names bis(triphenylphosphoranylidene)methane
Identifiers
CAS Number	7533-52-0;
3D model (JSmol)	Interactive image;
ChemSpider	9333895;
PubChem CID	11158793;
	InChI InChI=1S/C37H30P2/c1-7-19-32(20-8-1)38(33-21-9-2-10-22-33,34-23-11-3-12-24-34)31-39(35-25-13-4-14-26-35,36-27-15-5-16-28-36)37-29-17-6-18-30-37/h1-30H Key: KGZNGAKXXXNCGK-UHFFFAOYSA-N;
	SMILES C1=CC=C(C=C1)P(=C=P(C2=CC=CC=C2)(C3=CC=CC=C3)C4=CC=CC=C4)(C5=CC=CC=C5)C6=CC=CC=C6;
Properties
Chemical formula	C37H30P2
Molar mass	536.595 g·mol−1
Appearance	yellow solid
Density	1.205 g/cm3
Melting point	198–201 °C (388–394 °F; 471–474 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Hexaphenylcarbodiphosphorane is the organophosphorus compound with the formula C(PPh₃)₂ (where Ph = C₆H₅). It is a yellow, moisture-sensitive solid. The compound is classified as an ylide and as such carries significant negative charge on carbon. It is isoelectronic with bis(triphenylphosphine)iminium. The P-C-P angle is 131°.^[1] The compound has attracted attention as an unusual ligand in organometallic chemistry.^[2]

The pure compound has two crystalline phases: a metastable monoclinic C2 phase that is triboluminescent, and an orthorhombic P222 form that is not. Both polymorphs are photoluminescent, with respective peak wavelengths at 540 and 575 nm.^[3]

Preparation

The compound was originally prepared by deprotonation of the phosphonium salt [HC(PPh₃)₂]Br using potassium.^[4]

An improved procedure entails production of the same double phosphonium salt from methylene bromide. The double deprotonation is effected with potassium amide.^[5]

Related compounds

Methylenetriphenylphosphorane (CH₂=PPh₃), the parent Wittig reagent

References

^ Tonner, Ralf; Oexler, Florian; Neumueller, Bernhard; Petz, Wolfgang; Frenking, Gernot (2006). "Carbodiphosphoranes: The Chemistry of Divalent Carbon(0)". Angewandte Chemie International Edition. 45 (47): 8038–8042. doi:10.1002/anie.200602552. PMID 17075933.
^ Petz, W.; Frenking, G. (2010). "Carbodiphosphoranes and Related Ligands". Transition Metal Complexes of Neutral eta1-Carbon Ligands. Topics in Organometallic Chemistry. Vol. 30. pp. 49–92. Bibcode:2010tmcn.book...49P. doi:10.1007/978-3-642-04722-0_3. ISBN 978-3-642-04721-3. {{cite book}}: |journal= ignored (help)
^ Hardy, Gordon E.; Kaska, William C.; Chandra, B. P.; Zink, Jeffrey I. (March 1981). "Triboluminescence-structure relationships in polymorphs of hexaphenylcarbodiphosphorane and anthranilic acid, molecular crystals, and salts". Journal of the American Chemical Society. 103 (5): 1074–1079. doi:10.1021/ja00395a014.
^ Ramirez, Fausto; Desai, N. B.; Hansen, B.; McKelvie, N. (1961). "Hexaphenylcarbodiphosphorane, (C₆H₅)₃P:C:P(C₆H₅)₃". Journal of the American Chemical Society. 83 (16): 3539–40. doi:10.1021/ja01477a052.
^ Gruber, Marco; Bauer, Walter; Maid, Harald; Schöll, Kilian; Tykwinski, Rik R. (2017). "Synthetic and NMR Studies on Hexaphenylcarbodiphosphorane (Ph₃P=C=PPh₃)". Inorganica Chimica Acta. 468: 152–158. doi:10.1016/j.ica.2017.04.018.

[1] Tonner, Ralf; Oexler, Florian; Neumueller, Bernhard; Petz, Wolfgang; Frenking, Gernot (2006). "Carbodiphosphoranes: The Chemistry of Divalent Carbon(0)". Angewandte Chemie International Edition. 45 (47): 8038–8042. doi:10.1002/anie.200602552. PMID 17075933.

[2] Petz, W.; Frenking, G. (2010). "Carbodiphosphoranes and Related Ligands". Transition Metal Complexes of Neutral eta1-Carbon Ligands. Topics in Organometallic Chemistry. Vol. 30. pp. 49–92. Bibcode:2010tmcn.book...49P. doi:10.1007/978-3-642-04722-0_3. ISBN 978-3-642-04721-3. {{cite book}}: |journal= ignored (help)

[3] Hardy, Gordon E.; Kaska, William C.; Chandra, B. P.; Zink, Jeffrey I. (March 1981). "Triboluminescence-structure relationships in polymorphs of hexaphenylcarbodiphosphorane and anthranilic acid, molecular crystals, and salts". Journal of the American Chemical Society. 103 (5): 1074–1079. doi:10.1021/ja00395a014.

[4] Ramirez, Fausto; Desai, N. B.; Hansen, B.; McKelvie, N. (1961). "Hexaphenylcarbodiphosphorane, (C₆H₅)₃P:C:P(C₆H₅)₃". Journal of the American Chemical Society. 83 (16): 3539–40. doi:10.1021/ja01477a052.

[5] Gruber, Marco; Bauer, Walter; Maid, Harald; Schöll, Kilian; Tykwinski, Rik R. (2017). "Synthetic and NMR Studies on Hexaphenylcarbodiphosphorane (Ph₃P=C=PPh₃)". Inorganica Chimica Acta. 468: 152–158. doi:10.1016/j.ica.2017.04.018.

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