Definition: Pentachloride is a chemical compound with the formula Cl2Cl. It is a colorless, odorless, and toxic gas that can be produced from the reaction of chlorine with bromine. The chemical properties of pentachloride include its stability under pressure and at low temperatures. It is highly flammable and has a high boiling point, making it suitable for use in many industrial processes. Pentachloride is used in a variety of applications including as a flame retardant