Cadmium chloride
- Cadmium (II ) chloride
- Cadmiumdichlorid
White, odorless solid
Fixed
4.05 g · cm -3
568 ° C
960 ° C.
1400 g · l - 1 in water
Risk
Repealed because cancergen
88 mg · kg -1 ( LD50, rat, oral)
Template: Infobox chemical / molecular formula search available
Cadmium chloride is a chemical compound of cadmium and one of the chlorides. The colorless salt was crystallized in a characteristic trigonal crystal structure, which serves as a structural type for a number of other compounds.
Production and representation
Of anhydrous cadmium chloride can be obtained by the reaction of chlorine gas with heated cadmium.
Also, by dissolving cadmium or cadmium carbonate in hydrochloric acid and crystallization can win cadmium chloride. The result is a cadmium chloride hydrate, which can be dehydrated with thionyl chloride.
Properties
Cadmium chloride forms colorless, hygroscopic and highly water- soluble crystals. It crystallizes in a layered structure in the trigonal crystal system in the space group with the lattice parameters a = 3.85 Å and c = 17.46 Å. This structure consists of a cubic close packing of chloride anions, in which the cadmium cations classify each second layer in the octahedral sites ( layer sequence ABCABC, coordination type = 6:3 ). Thus, the cadmium ions are octahedrally surrounded by six chloride ions. Each chloride ion forms the apex of a trigonal pyramid with three cadmium ions as base. The CdCl2 structure is often used as a reference structure. In this structure, in particular the transition metal chlorides crystallize such as manganese (II ) chloride, iron ( II) chloride or zinc chloride, as well as magnesium chloride, zinc bromide and nickel ( II) iodide.
Use
Cadmium chloride solutions adsorb hydrogen sulfide. It is also used in electroplating, microscopy, photography, and as a starting material for the production of cadmium pigments.
Cadmium chloride acts as a catalyst in Biginelli reactions for the preparation of 3,4- dihydropyrimidine -2 ( 1H) -ones.
Safety
Cadmium chloride is a highly toxic and environmentally hazardous substance, are carcinogenic, mutagenic and toxic for reproduction can work. The substance is classified as very dangerous carcinogenic substance in Annex II, No. 6 of the Hazardous Substances Ordinance ( Ordinance on Hazardous Substances ) and may be produced or used in closed systems. An acute toxic effect of which is a strong irritant to the respiratory tract after inhalation of vapors or aerosols to pulmonary edema. A chronic poisoning leads to damage to the kidneys, liver and lungs. Optical characteristic of cadmium poisoning is the formation of a yellow hem on the neck of a tooth by sulfidic cadmium compounds. For rats, a LD50 of 88 mg / kg (oral, anhydrous cadmium chloride ) is indicated. Moreover, it is extremely toxic to many aquatic organisms (bacteria, algae, crustaceans ).