Palladium (II) chloride

Crystal structure
	__ Pd 2+ __ Cl -
General
Surname	Palladium (II) chloride
other names	Palladium dichloride; Palladium dichloratum (Latin);
Ratio formula	PdCl 2
Brief description	red to dark brown powder or crystals
External identifiers / databases
EC number	231-596-2
ECHA InfoCard	100.028.724
PubChem	24290
Wikidata	Q419904
properties
Molar mass	177.31 g mol −1
Physical state	firmly
density	4.0 g cm −3 (20 ° C)
Sublimation point	590 ° C
solubility	practically insoluble in water (anhydrous); soluble in water (dihydrate);
safety instructions
H and P phrases	H: 290-302-317-318-410
	P: 280-302 + 352-305 + 351 + 338
Toxicological data	570 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Palladium (II) chloride is the palladium salt of hydrochloric acid .

Extraction and presentation

Palladium (II) chloride is obtained by dissolving metallic palladium in aqua regia or in hydrochloric acid in the presence of chlorine . Alternatively, it can be obtained by heating sponge palladium in chlorine gas at 500 ° C.

properties

Physical Properties

α-Palladium (II) chloride forms red rhombohedral crystals which slowly dissolve in water with a red color to form PdCl ₂ (H ₂ O) ₂ . It is also soluble in ethanol and acetone . It dissolves quickly in hydrochloric acid. It is almost odorless and slightly hazardous to water.

Chemical properties

Palladium (II) chloride decomposes from 600 ° C into palladium and chlorine. It dissolves in hydrochloric acid and forms a tetrachloropalladate [PdCl ₄ ] ²⁻ :

{\ displaystyle \ mathrm {PdCl_ {2} + 2Cl ^ {-} \ longrightarrow [PdCl_ {4}] ^ {2-}}}

This catalyzes various organic reactions, such as the oxidation of ethylene to acetaldehyde ( Wacker-Hoechst process ).

When introducing hydrogen sulfide , brown-black palladium monosulfide PdS precipitates.

When heated with sulfur to 450 to 500 ° C, formation of palladium disulfide PdS ₂ .

When ammonia is introduced into the aqueous solution, tetraammine palladium (II) chloride [Pd (NH ₃ ) ₄ ] Cl _{2 is formed} , even with dry PdCl ₂ .

use

Palladium (II) chloride is the starting material for various palladium compounds. It is also used for the detection of carbon monoxide . To do this, paper is soaked in a very dilute PdCl ₂ solution. This is colored black by CO or other reducing substances with the deposition of metallic palladium. It is also used in electroplating solutions and for porcelain pictures.

Crystalline α-palladium chloride

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on palladium (II) chloride in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .
↑ Data sheet Palladium (II) chloride (PDF) from Merck , accessed on August 15, 2016.
↑ ^a ^b ^c ^d Cotton, Simon; The Chemistry of Precious Metals ; Springer 1997.
^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on palladium (II) chloride in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .

[Merck-2] Data sheet Palladium (II) chloride (PDF) from Merck , accessed on August 15, 2016.

[Cotton-3] Cotton, Simon; The Chemistry of Precious Metals ; Springer 1997.

[4] AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 .