Chlorine monofluoride is a volatileinterhalogen compound with the chemical formula ClF. It is a colourless gas at room temperature and is stable even at high temperatures. When cooled to −100 °C, ClF condenses as a pale yellow liquid. Many of its properties are intermediate between its parent halogens, Cl2 and F2.[1]
Geometry
The molecular structure in the gas phase was determined by microwave spectroscopy; the bond length is re = 1.628341(4) Å.[2]
The bond length in the crystalline ClF is 1.628(1) Å; the lengthening relative to the free molecule is due to an interaction of the type F-Br···ClMe with a distance of 2.640(1) Å. In its molecular packing it shows very short intermolecular Cl···Cl contacts of 3.070(1) Å between neighboring molecules.[3]
FCl can also chlorofluorinate compounds, either by addition across a multiple bond or via oxidation. For example, it adds fluorine and chlorine to the carbon of carbon monoxide, yielding carbonyl chloride fluoride: