Cl2O7

Dichlorine heptoxide, Cl2O7, is an inorganic compound that serves as the anhydride of perchloric acid. It is a colorless, fuming liquid at room temperature, with both chlorine atoms in the +7 oxidation state. The molecule is highly reactive and a strong oxidizer.

Properties and reactivity

Cl2O7 readily hydrolyzes in contact with water to form perchloric acid (HClO4). It is extremely reactive with moisture and can react exothermically with reducing agents and many organic materials. Due to its instability and tendency to release fumes, it is typically handled only under strictly dry conditions and in facilities equipped for handling highly reactive oxidizers.

Preparation

In practice, Cl2O7 is prepared by dehydration of perchloric acid using strong drying agents such as phosphorus pentoxide or concentrated sulfuric acid. The dehydration is performed under carefully controlled conditions, and the product is usually used in situ because Cl2O7 is unstable and decomposes if isolated.

Uses

The primary role of Cl2O7 is as the anhydride of perchloric acid and as a potent oxidizing agent in select chemical syntheses. Its use is limited to specialized research or industrial processes due to its hazards and the need for stringent containment.

Safety and handling

Cl2O7 is highly reactive, corrosive, and capable of violent reactions with water, organic substances, or reducing agents. It fumes in air and can pose serious health and safety risks. Handling requires dry, inert atmospheres, compatible equipment, and appropriate protective measures.

Occurrence

Dichlorine heptoxide is not a material that occurs naturally in the environment and is produced under controlled laboratory or industrial conditions.