Chlorine trifluoride
Chlorine trifluoride is an interhalogen compound with the formula ClF3. This colourless, 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). The compound is primarily of interest as a component in rocket fuels, in plasmaless cleaning and etching operations in the semiconductor industry, in nuclear reactor fuel processing, and other industrial operations.
Preparation, structure, and properties
It was first reported in 1930 by Ruff and Krug who prepared it by fluorination of chlorine; this also produced ClF and the mixture was separated by distillation.
ClF3 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.
Chlorine pentafluoride
Chlorine pentafluoride is an interhalogen compound with formula ClF5. This colourless gas is an strong oxidant that was once a candidate oxidizer for rockets. The molecule adopts a square pyramidal structure with C4v symmetry, as confirmed by its high resolution 19F NMR spectrum.
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:
NiF2 catalyzes this reaction.
Certain metal fluorides, MClF4 (i.e. KClF4, RbClF4, CsClF4) react with F2 to produce ClF5 and the corresponding alkali metal fluoride.
Reactions
In a highly exothermic reaction, water hydrolyses ClF5 to produce chloryl fluoride and hydrogen fluoride:
It is also a strong fluorinating agent. At room temperature it reacts readily with all elements except noble gases, nitrogen, oxygen and fluorine.
See also
References
External links
Common Look and Feel
The Government of Canada’s Common Look and Feel (CLF) Standards for the Internet governed the branding, usability & accessibility standards for its websites and web applications from 2000 - 2010. It comprised the following four parts, now rescinded:
Government of Canada Web Standards
The Common Look and Feel (CLF) Standards for the Internet have been replaced with four Web Standards that incorporate current web practices such as WCAG 2.0, as well as designing for a plethora of devices, browsers and assistive technologies through which people navigate the Web.
Podcasts:
