Palladium dichloride (strem),
Dibenzylideneacetone (Avocado),
Sodium acetate trihydrate (Aldrich, 99+%),
Methanol.

Dibenzylideneacetone (4.60 g, 19.6 mmol) and sodium acetate trihydrate (6.47 g, 47.5 mmol) were placed in a one necked 500 mL round bottomed flask with a sidearm and the flask fitted with a stopper. The side arm was attached to a double manifold Schlenk line and the flask cycled three times vacuum/Argon. Under a flow of argon the stopper was removed, methanol (150 mL) was added and the flask re-stoppered. The reactants were dissolved at 50 ^oC. Under a flow of argon the stopper was removed for a second time, PdCl₂ (1.05 g, 5.9 mmol) was added and the flask was re-stoppered again. The side arm tap and Schlenk line tap were both left open to argon. An oil bubbler was attached to a second tap of the Schlenk line and the tap opened to argon. The mixture was heated at 40 ^oC with stirring under an oil bubbler presure of argon for 4 h after which a dark purple/black precipitate had formed. The precipitate was collected by filtration on a Buchner funnel and washed 1^st with water (70 mL) and 2^nd with acetone (70 mL). The product was dried under vacuum to yield 3.12 g of a dark purple solid (92% yield).

This procedure works well and has been repeated by members of the group 3 times always on the same scale. The complex is slightly sensitive to air and can be stored in a screw top jar for 3 months before decomposition occurs. Recrystallisation of the partially decomposed product yields pure compound. If kept in an air tight vessel under argon the product can be stored indefinitely without decomposition. The crude product has a stoichiometry of Pd(dba)₂ (see other ref.) and can be used without further purification. If desired the crude product can be recrystallised from chloroform, benzene or toluene all of which yield a compound of stoichiometry Pd₂(dba)₃(solvent) (see lead ref.). The solvent can be removed from the crystaline material by placing under dynamic vacuum (1x10^-2) for 5 h.

No data has been collected on this product as common analytical methods do not help in establishing the stoichiometry of the product. The Previously published work has shown the various stoichiometries to be correct by means of X-ray diffraction studies and elemental analysis (see refs.).

Toshinao, U.; Kawazura, H.; Ishii, Y. J. Organomet. Chem., 1974, 65, 253.

Takahashi, Y.; Ito, T.; Sakai, S.; Ishii, Y. J. Chem. Soc. Chem. Commun., 1970, 1065.