Palladium(II) chloride
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| Names | |
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| Other names
Palladium dichloride, Palladous chloride
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| Identifiers | |
7647-10-1 
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| 3D model (Jmol) | Interactive image |
| ECHA InfoCard | 100.028.724 |
| EC Number | 231-596-2 |
| PubChem | 24290 |
| RTECS number | RT3500000 |
| UNII |
N9214IR8N7 
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| Properties | |
| PdCl2 | |
| Molar mass | 177.326 g/mol (anhydrous) 213.357 g/mol (dihydrate) |
| Appearance | dark red solid hygroscopic (anhydrous) dark brown crystals (dihydrate) |
| Density | 4.0 g/cm3 |
| Melting point | 679 °C (1,254 °F; 952 K) (decomposes) |
| soluble in trace amounts, better solubility in cold water | |
| Solubility | soluble in organic solvents dissolves rapidly in HCl |
| −38.0·10−6 cm3/mol | |
| Structure | |
| rhombohedral | |
| square planar | |
| Hazards | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
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LD50 (median dose)
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2704 mg/kg (rat, oral) |
| Related compounds | |
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Other anions
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Palladium(II) fluoride Palladium(II) bromide Palladium(II) iodide |
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Other cations
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Nickel(II) chloride Platinum(II) chloride Platinum(II,IV) chloride Platinum(IV) chloride |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is ?) |
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| Infobox references | |
Palladium(II) chloride, also known as palladium dichloride and palladous chloride, are the chemical compounds with the formula PdCl2. PdCl2 is a common starting material in palladium chemistry – palladium-based catalysts are of particular value in organic synthesis. It is prepared by chlorination of palladium.
Two forms of PdCl2 are known. In both forms, the palladium centres adopt the square-planar coordination geometry that is characteristic of Pd(II). Furthermore, in both forms, the Pd(II) centres are linked by μ2-chloride bridges. The α-form of PdCl2 is a polymer, consisting of "infinite" slabs or chains. The β-form of PdCl2 is molecular, consisting of an octahedral cluster of six Pd atoms. Each of the twelve edges of this octahedron is spanned by Cl−. PtCl2 adopts similar structures, whereas NiCl2 adopts the CdCl2 motif, featuring hexacoordinated Ni(II).
Palladium(II) chloride is prepared by dissolving palladium metal in aqua regia or hydrochloric acid in the presence of chlorine. Alternatively, it may be prepared by heating palladium sponge metal with chlorine gas at 500 °C.
Palladium(II) chloride is a common starting point in the synthesis of other palladium compounds. It is not particularly soluble in water or non-coordinating solvents, so the first step in its utilization is often the preparation of labile but soluble Lewis base adducts, such as those derived from acetonitrile or benzonitrile. The acetonitrile complex is prepared by treating PdCl2 in refluxing acetonitrile:
Although occasionally recommended, inert-gas techniques are not necessary if the complex is to be used in situ. As an example, bis(triphenylphosphine)palladium(II) dichloride may be prepared from palladium(II) chloride by reacting it with triphenylphosphine in benzonitrile:
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