Английская Википедия:Hexaphenylcarbodiphosphorane
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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
