Water → Palladium

HRID 1593352Notes

Reaction equation

HRID 1593352 reaction equation
O.[Pd:2].[Pd+2].[C:4]([O-:7])(=O)[CH3:5].[Pd+2].[C:9]([O-:12])(=O)[CH3:10].[CH2:13]([C:17]([CH3:19])=[O:18])C(C)C>>[Pd:2].[CH3:19]/[C:17](/[O-:18])=[CH:13]/[C:4]([CH3:5])=[O:7].[CH3:19]/[C:17](/[O-:18])=[CH:13]/[C:9]([CH3:10])=[O:12].[Pd+2:2]

Participants

7

Reactant 5

HCID 962WaterHCID 7909Methyl Isobutyl KetoneHCID 23938PalladiumHCID 105144Allyl(1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene)chloropalladium(II)HCID 167845palladium(II) acetate

Product 2

HCID 23938PalladiumHCID 5486778Palladium acetylacetonate

Procedure

In the prior art, preparation of metal colloids has typically been carried out in aqueous solution in the presence of additives such as surfactants, oil microemulsions, nonpolar water-soluble polymers or amphiphilic block or graft copolymers. In addition, preparation of palladium (0) sols with particle diameter ranges between 7 nm and 260 nm has been carried out by thermal decomposition of organopalladium compounds in various organic solvents using refluxing conditions without any additives. This was accomplished by dissolving organopalladium compounds, such as bis(2,4-pentanedionate) palladium (II) [Pd(acac)2] or palladium acetate, in various organic solvents and refluxing the solutions at their boiling point for a period of minutes to several hours. See for example Esumi et al. in Langmuir, 5, 1, 268 (1989) and Tano et al. in J. Colloid Interface Sci., 133, 2, 530 (1989). Stable and relatively monodisperse palladium (0) sols, with particle diameter ranges between 8 nm and 10 nm were only obtained from [Pd(acac)2] in the organic solvent methyl isobutyl ketone which exhibits a high dipole moment of D˜2.7 and a relatively low boiling point of 115.9° C. Bimetallic Pd—Cu colloids, Pd—Cu2O, such as from mixed palladium acetate and copper (II) acetate have similarly been prepared by thermal decomposition in various organic solvents without any additives. See, for example, Esumi et al in Chem. Mater., 2, 5, 564, (1990). The average diameters of the Pd—Cu2O sols ranged between 50 and 130 nm with a decrease of the molar ratio of palladium acetate in the mixed acetates. The prior art of Esumi et al. and Tano et al. describe a critical thermal decomposition temperature for formation of stable metal colloids that ranges between 110° C. and 116° C. in organic solvents of low viscosity, i.e., significantly less than 10 centipoises.

Workup

  1. customIn the prior art, preparation of metal colloids
  2. temperatureusing refluxing conditions without any additives
  3. customto several hours

Sources & evidence

ORD record
ord-629dd07411d645c881f1e25ba8b3a62d
Source dataset
uspto-grants-2007_11
Patent number
US07297448B2

Reaction notes

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