Chlorine trifluoride

Chlorine trifluoride is an interhalogen compound with the formula . 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 temperature). Despite being famous for its extreme oxidation properties and igniting many things, chlorine trifluoride is not combustible itself. The compound is primarily of interest in plasmaless cleaning and etching operations in the semiconductor industry, in nuclear reactor fuel processing, historically as a component in rocket fuels, and various other industrial operations owing to its corrosive nature. It was first reported in 1930 by Ruff and Krug who prepared it by fluorination of chlorine; this also produced Chlorine monofluoride (ClF) and the mixture was separated by distillation. The molecular geometry of is approximately T-shaped, with one short bond (1.598 Å) and two long bonds (1.698 Å). This structure agrees with the prediction of VSEPR theory, which predicts lone pairs of electrons as occupying two equatorial positions of a hypothetic trigonal bipyramid. The elongated Cl-F axial bonds are consistent with hypervalent bonding. Pure is stable to in quartz vessels; above this temperature, it decomposes by a free radical mechanism to its constituent elements. Reactions with many metals give chlorides and fluorides. With phosphorus, it yields phosphorus trichloride () and phosphorus pentafluoride (), while sulfur yields sulfur dichloride () and sulfur tetrafluoride (). also reacts with water to give hydrogen fluoride and hydrogen chloride, along with oxygen and oxygen difluoride (): It will also convert many metal oxides to metal halides and oxygen or oxygen difluoride. It occurs as a ligand in the complex . One of the main uses of is to produce uranium hexafluoride, , as part of nuclear fuel processing and reprocessing, by the fluorination of uranium metal: The compound can also dissociate under the scheme: In the semiconductor industry, chlorine trifluoride is used to clean chemical vapour deposition chambers.