Allylpalladium chloride dimer

Allylpalladium(II) chloride dimer (APC) is a chemical compound with the formula [(η3-C3H5)PdCl]2. This yellow air-stable compound is an important catalyst used in organic synthesis.[1] It is one of the most widely used transition metal allyl complexes.

Allylpalladium(II) chloride dimer
Allylpalladium-chloride-dimer-3D-balls.png
-AllPdCl-2.png
Names
IUPAC name
Allylpalladium(II) chloride dimer
Other names
Allylpalladium chloride dimer
bis(allyl)di-μ-chloro-dipalladium(II)
APC
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.423
EC Number
  • 234-579-8
Properties
C6H10Cl2Pd2
Molar mass 365.85 g/mol
Appearance Pale yellow, crystalline solid
Density Solid
Melting point decomp at 155-156 °C
Insoluble
Solubility in other solvents Chloroform
benzene
acetone
methanol
Hazards
Safety data sheet http://www.colonialmetals.com/pdf/5048.pdf
GHS pictograms GHS07: Harmful
GHS Signal word Warning
H302, H312, H315, H319, H332, H335
P261, P264, P270, P271, P280, P301+312, P302+352, P304+312, P304+340, P305+351+338, P312, P321, P322, P330, P332+313, P337+313, P362, P363, P403+233, P405, P501
Related compounds
Related compounds
3-allyl)(η5 – cyclopentadienyl)palladium(II)
di-μ-chlorobis(crotyl)dipalladium
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Synthesis and reactionsEdit

The compound is prepared by purging carbon monoxide through a methanolic aqueous solution of sodium tetrachloropalladate (prepared from palladium(II) chloride and sodium chloride), and allyl chloride.[1]

2 Na2PdCl4   +   2 CH2=CHCH2Cl   +   2 CO   +   2 H2O   →   [(η3-C3H5)PdCl]2   +   4 NaCl   +   2 CO2   +   4 HCl

APC reacts with sources of cyclopentadienyl anion to give the corresponding 18e complex cyclopentadienyl allyl palladium:

[(η3-C3H5)PdCl]2   +   2 NaC5H5   →   2 [(η5-C5H5)Pd(η3-C3H5)]   +   2 NaCl


The dimer reacts with a variety of Lewis bases (:B) to form adducts (η3-C3H5)PdCl:B. Its reaction with pyridine and the corresponding enthalpy are:

1/2[(η3-C3H5)PdCl]2 + :NC5H5 → (η3-C3H5)PdCl:NC5H5   ΔH= -30.1 kJ mol−1

This enthalpy corresponds to the enthalpy change for a reaction forming one mole of the product, (η3-C3H5)PdCl:NC5H5, from the acid dimer. The dissociation energy for the Pd dimer, which is an energy contribution prior to reaction with the donor,

[(η3-C3H5)PdCl]2 →2 (η3-C3H5)PdCl

has been determined by the ECW model to be 28 kJ mol−1

ReferencesEdit

  1. ^ a b Tatsuno, Y.; Yoshida, T.; Otsuka, S. "(η3-allyl)palladium(II) Complexes" Inorganic Syntheses, 1990, volume 28, pages 342-345. ISBN 0-471-52619-3