Tetrakis(triphenylphosphine)palladium(0)



Tetrakis(triphenylphosphine)palladium(0)
General
Systematic name Tetrakis(triphenylphosphine)palladium(0)
Other names TPP palladium(0)
Molecular formula Pd
Molar mass 1155.56 g/mol
Appearance Bright yellow crystals
CAS number [14221-01-3]
Properties
Density and phase  ? g/cm3, ?
water Insoluble
In chloroform Approx 5 g/100ml
Melting point decomposes around 115 °C
Structure
Molecular shape tetrahedral
Coordination
geometry 		four Pd(0)
atom in a tetrahedral geometry
Crystal structure  ?
Dipole moment 0 D
Hazards
MSDS External MSDS
Main hazards PPh3 is an irritant
NFPA 704
1
2
0
 
R/S statement S24/25
RTECS number Unregistered
Supplementary data page
Structure and
properties 		εr, etc.
Thermodynamic
data 		Phase behaviour
Solid, liquid, gas
Spectral data MS
Related compounds
Related complexes tris(dibenzylideneacetone)dipalladium(0)
Related compounds triphenylphosphine
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Tetrakis(triphenylphosphine)palladium(0) is the chemical compound Pd[P(C6H5)3]4, often abbreviated Pd(PPh3)4, or even PdP4. It is a bright yellow crystalline solid that becomes brown upon decomposition in air.

Preparation, structure, and properties

This complex is prepared in two steps from Pd(II) precursors:

PdCl2 + 2 PPh3 → cis-PdCl2(PPh3)2
cis-PdCl2(PPh3)2 + 2 PPh3 + 2.5 N2H4 → Pd(PPh3)4 + 0.5 N2 + 2 N2H5+Cl-

hydrazine can be employed.

The four 18e complexes.[1] The corresponding complexes Ni(PPh3)4 and Pt(PPh3)4 are also well known. Such complexes reversibly dissociate PPh3 ligands in solution, releasing the 16e M(PPh3)3. Thus, reactions attributed to Pd(PPh3)4 in fact arise from Pd(PPh3)3 or even Pd(PPh3)2.

If the tetrakis(triphenylphosphine)palladium (0) is an orange brown, triturate with methanol and filter to give the desired yellow powder. Store under nitrogen in the fridge.

Applications

Pd(PPh3)4 is widely used as a oxidative addition of an aryl halide to the Pd(0) center:

Pd(PPh3)4 + ArBr → PdBr(Ar)(PPh3)2 + 2 PPh3

References

  1. ^ C. Elschenbroich, A. Salzer ”Organometallics : A Concise Introduction” (2nd Ed) (1992) from Wiley-VCH: Weinheim. ISBN 3-527-28165-7
  2. ^ Homogeneous Catalysis: Understanding the Art” by P. W. van Leeuwen, Springer; 2005. ISBN 1-4020-3176-9
 
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