Chlorine pentafluoride is an interhalogen compound with formula . This colourless gas is a strong oxidant that was once a candidate oxidizer for rockets. The molecule adopts a square pyramidal structure with C_4v

symmetry Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant und ...

, as confirmed by its high-resolution ¹⁹F NMR spectrum. It was first synthesized in 1963.

Preparation

Some of the earliest research on the preparation was classified. It was first prepared by fluorination of chlorine trifluoride at high temperatures and high pressures: : : : : catalyzes this reaction. Certain metal fluorides, , e.g. (potassium tetrafluorochlorate(III)), (rubidium tetrafluorochlorate(III)), (caesium tetrafluorochlorate(III)), react with to produce and the corresponding

alkali metal The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...

fluoride.

Reactions

In a highly exothermic reaction, reacts with water to produce chloryl fluoride and

hydrogen fluoride Hydrogen fluoride (fluorane) is an Inorganic chemistry, inorganic compound with chemical formula . It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid. It is the principal industrial source of fluori ...

: : It is also a strong fluorinating agent. At room temperature it reacts readily with all elements (including otherwise "inert" elements like

platinum Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...

and

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

) except

noble gases The noble gases (historically the inert gases, sometimes referred to as aerogens) are the members of group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) and, in some cases, oganesson (Og) ...

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

and

fluorine Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...

Uses

Rocket propellant

Chlorine pentafluoride was once considered for use as an oxidizer for rockets. As a propellant, it has a higher maximum

specific impulse Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine, such as a rocket engine, rocket using propellant or a jet engine using fuel, generates thrust. In general, this is a ratio of the ''Impulse (physics), ...

than , but with the same difficulties in handling. Due to the hazardous nature of chlorine pentafluoride and the large amounts of

in the exhaust, it has yet to be used in a large scale rocket propulsion system.

Safety

Chlorine pentafluoride is highly toxic. It is a strong irritant to skin, eyes and mucous membranes. It is very corrosive. Causes severe and painful skin, eye and respiratory tract burns. May cause lungs damage, toxic pneumonitis and permanent blindness. It is fatal if inhaled or absorbed through skin. Containers with chlorine pentafluoride may explode when heated. Ruptured cylinders may rocket violently. Chlorine pentafluoride causes other symptoms like nausea, vomiting and dyspnea.https://www.chemicalbook.com/ChemicalProductProperty_EN_CB4364157.htm Chlorine pentafluoride reacts violently with water or moisture in the air and even water ice at (to produce corrosive hydrofluoric acid and toxic

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

gas),

nitric acid Nitric acid is an inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into nitrogen oxide, oxides of nitrogen. Most com ...

(even at −100 °C), metals and organic materials. It is a strong oxidizer. It does not burn, but support burning. On catching fire or heated to decomposition, it emits corrosive and very toxic gases. Vapors from liquefied gas are initially heavier than air and spread along the floor. These are strong oxidizers and will react vigorously or explosively with many materials including fuels. May ignite flammable materials (wood, paper, oil, clothing, etc.).

References

External links

National Pollutant Inventory - Fluoride and compounds fact sheetNew Jersey Hazardous Substance Fact SheetWebBook page for ClF5
{{DEFAULTSORT:Chlorine Pentafluoride Fluorides Highly-toxic chemical substances Inorganic chlorine compounds Interhalogen compounds Rocket oxidizers Fluorinating agents Oxidizing agents Chlorine(V) compounds Substances discovered in the 1960s