Carbonyl chloride fluoride (COClF) is a highly toxic, colorless, and volatile gas that serves as a structural hybrid between phosgene (carbonyl chloride) and carbonyl fluoride. First synthesized in 1946, it belongs to the carbon oxohalide family but remains less commonly used than its symmetrical counterparts due to historical production difficulties. Physical and Chemical Properties Chemical Formula: COClFCOClF Molecular Weight: Boiling Point: Melting Point:
Reactivity: It is significantly more reactive than phosgene or carbonyl fluoride because its lower structural symmetry makes it unstable.
Moisture Sensitivity: The compound is highly hygroscopic. It reacts violently with water, steam, or moisture to release dangerous, corrosive fumes of hydrochloric acid ( ), hydrofluoric acid ( ), and carbon dioxide ( CO2CO sub 2
Historically, carbonyl chloride fluoride was difficult to isolate. It is usually synthesized using one of the following methods: Halogen Exchange: Passing phosgene ( COCl2COCl sub 2 ) over fluorinating agents like calcium fluoride ( CaF2CaF sub 2
) or antimony halides at high temperatures. This typically requires complex low-temperature distillation to separate it from unreacted materials. Trichlorofluoromethane Reaction: Reacting (Freon-11) with sulfur trioxide ( SO3SO sub 3 ), yielding roughly a 60% output.
Adduct Decomposition: A modern, high-yield alternative involves decomposing an oxygen-bridged
donor-acceptor chemical adduct at room temperature under a vacuum. Chemical Uses
Despite being difficult to handle, carbonyl chloride fluoride is an effective chemical intermediate. It is primarily utilized in specialized organic synthesis, particularly for triggering ring-opening reactions in epoxides to create fluorinated haloalkyl chloroformates. Severe Health Hazards
Carbonyl chloride fluoride is a potent choking agent and respiratory poison.
Leave a Reply