Chlorine oxide trifluoride or chlorine trifluoride oxide is a corrosive liquid molecular compound with formula ClOF₃. It was developed secretly as a rocket fuel oxidiser.

Production

Chlorine oxide trifluoride was originally made at

Rocketdyne Rocketdyne was an American rocket engine design and production company headquartered in Canoga Park, California, Canoga Park, in the western San Fernando Valley of suburban Los Angeles, California, Los Angeles, in southern California. The Rocke ...

by treating

dichlorine monoxide Dichlorine monoxide is an inorganic compound with the molecular formula Cl2O. It was first synthesised in 1834 by Antoine Jérôme Balard, who along with Gay-Lussac also determined its composition. In older literature it is often referred to as c ...

with

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...

. Other substances that could react with fluorine to make it includes

sodium chlorite Sodium chlorite (NaClO2) is a chemical compound used in the manufacturing of paper and as a disinfectant. Use The main application of sodium chlorite is the generation of chlorine dioxide for bleaching and stripping of textiles, pulp, and pa ...

(NaClO₂), and

chlorine nitrate Chlorine nitrate, with chemical formula ClNO3 is an important atmospheric gas present in the stratosphere. It is an important sink of chlorine that contributes to the depletion of ozone. It explosively reacts with metals, metal chlorides, alcohol ...

(ClONO₂). The first published production method was a reaction of dichlorine monoxide with

oxygen difluoride Oxygen difluoride is a chemical compound with the formula . As predicted by VSEPR theory, the molecule adopts a "bent" molecular geometry. It is strong oxidizer and has attracted attention in rocketry for this reason. With a boiling point of -144.7 ...

(OF₂). Yet other production methods are reactions between ClO₂F or ClO₃F and chlorine fluorides. A safer approach is the use

with fluorine.

Reactions

As a

Lewis base A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

it can lose a fluoride ion to Lewis acids, yielding the difluorooxychloronium(V)

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

(ClOF₂⁺). Compounds with this include: ClOF₂BF₄, ClOF₂PF₆, ClOF₂AsF₆, ClOF₂SbF₆, ClOF₂BiF₆, ClOF₂VF₆, ClOF₂NbF₆, ClOF₂TaF₆, ClOF₂UF₆, ClOF₂, (ClOF₂)₂SiF₆, ClOF₂MoOF₅, ClOF₂Mo₂O₄F₉, ClOF₂PtF₆. Functioning as a Lewis acid, it can gain a fluoride ion from a strong base to yield a tetrafluorooxychlorate(V) anion: ClOF₄⁻ ion. These include KClOF₄, RbClOF₄, and CsClOF₄. This allows purification of ClOF₃, as at room temperature a solid complex is formed, but this decomposes between 50 and 70 °C. Other likely impurities either will not react with alkali fluoride, or if they do will not easily decompose. Chlorine trifluoride oxide fluoridates various materials such as chlorine monoxide, chlorine, glass or quartz. ClOF₃ + Cl₂O → 2ClF + ClO₂F; 2ClOF₃ + 2Cl₂ → 6ClF + O₂ at 200 °C Chlorine trifluoride oxide adds to chlorine fluorosulfate, ClOF₃ + 2ClOSO₂F → S₂O₅F₂ + FClO₂ + 2ClF. The reaction also produces SO₂F₂. Chlorine trifluoride oxide can fluoridate and add oxygen in the same reaction, reacting with molybdenum pentafluoride,

silicon tetrafluoride Silicon tetrafluoride or tetrafluorosilane is a chemical compound with the formula Si F4. This colorless gas is notable for having a narrow liquid range: its boiling point is only 4 °C above its melting point. It was first prepared in 1771 ...

tetrafluorohydrazine Tetrafluorohydrazine or perfluorohydrazine, , is a colourless, reactive inorganic gas. It is a fluorinated analog of hydrazine. It is a highly hazardous chemical that explodes in the presence of organic materials. Tetrafluorohydrazine is manufact ...

(over 100 °C), HNF₂, and F₂NCOF. From HNF₂ the main result was NF₃O. From MoF₅, the results were MoF₆ and MoOF₄. It reacts explosively with hydrocarbons. With small amounts of water, ClO₂F is formed along with HF. Over 280 °C ClOF₃ decomposes to oxygen and

chlorine trifluoride Chlorine trifluoride is an interhalogen compound with the formula ClF3. This colorless, poisonous, corrosive, and extremely reactive gas condenses to a pale-greenish yellow liquid, the form in which it is most often sold (pressurized at room temp ...

Properties

The boiling point of chlorine trifluoride oxide is 29 °C. The shape of the molecule is a

trigonal bipyramid In geometry, the triangular bipyramid (or dipyramid) is a type of hexahedron, being the first in the infinite set of face-transitive bipyramids. It is the dual of the triangular prism with 6 isosceles triangle faces. As the name suggests, i ...

, with two fluorine atoms at the top and bottom (apex) (F_a) and an electron pair, oxygen and fluorine (F_e) on the equator. The Cl=O bond length is 1.405 Å, Cl-F_e 1.603 Å, other Cl-F_a 1.713 Å, ∠F_eClO=109° ∠F_aClO=95°, ∠F_aClF_e=88°. The molecule is polarised, Cl has a +1.76 charge, O has −0.53, equatorial F has −0.31 and apex F has −0.46. The total dipole moment is 1.74 D.

References

{{Fluorine compounds Oxyfluorides Chlorine(V) compounds