Copper(II) chloride

Copper(II) chloride, also known as cupric chloride, is a chemical compound with the formula CuCl₂. It is a light brown solid that slowly absorbs moisture to form a blue-green dihydrate. This compound is used in various applications, including as a catalyst in organic synthesis and as a fungicide.

Structure and Properties

Copper(II) chloride is a coordination compound that can exist in an anhydrous form or as a dihydrate. The anhydrous form is a brown powder, while the dihydrate is blue-green crystals. The compound is highly soluble in water, forming a blue solution due to the presence of the [Cu(H₂O)₄Cl₂] complex.

The structure of copper(II) chloride in its anhydrous form consists of a polymeric chain, where each copper atom is coordinated to two chloride ions and two bridging chloride ions, forming a distorted tetrahedral geometry.

Preparation

Copper(II) chloride can be prepared by the direct chlorination of copper:

<math>\text{Cu} + \text{Cl}_2 \rightarrow \text{CuCl}_2</math>

Alternatively, it can be produced by dissolving copper(II) oxide or copper(II) carbonate in hydrochloric acid:

<math>\text{CuO} + 2\text{HCl} \rightarrow \text{CuCl}_2 + \text{H}_2\text{O}</math>

Applications

Copper(II) chloride is used in a variety of applications:

• Catalysis: It is used as a catalyst in organic reactions, such as the Sandmeyer reaction and in the synthesis of chlorine-containing compounds.
• Textile Industry: It is used in the dyeing and printing of textiles.
• Fungicide: Copper(II) chloride is used as a fungicide in agriculture.
• Photography: It is used in some photographic processes.

Safety and Handling

Copper(II) chloride is toxic and should be handled with care. It can cause irritation to the skin, eyes, and respiratory tract. Proper protective equipment, such as gloves and goggles, should be used when handling this compound.

Also see

• Copper(I) chloride
• Copper(II) sulfate
• Chloride
• Coordination complex