Interhalogen Compounds
Compounds of two halogens such as ClF3 and IF7.
Compounds of two halogens such as ClF3 and IF7.
Interhalogen compounds form when two different halogens combine, with general formulas XX', XX'3, XX'5 and XX'7, where the heavier halogen is the central atom. Examples include ClF, BrF3, IF5 and IF7. Most are more reactive than the parent halogens, although fluorine is more reactive than any of them, and they are powerful fluorinating agents. Their shapes follow VSEPR theory: ClF3 is T-shaped, BrF5 is square pyramidal and IF7 is pentagonal bipyramidal. Bromine trifluoride is used in processing uranium fuel.
Key ideas: Types XX', XX'3, XX'5 and XX'7, where X is the larger halogen: ClF, BrF3, ClF3, IF5, IF7. Larger central atom allows more fluorines; IF7 is pentagonal bipyramidal, ClF3 T-shaped, BrF5 square pyramidal, ICl and IBr linear. They are more reactive than the parent halogens (except F2) because X-X' bond is weaker than X-X. Hydrolysis gives halide plus oxoanion. ClF3 is an extremely strong fluorinating agent.
Common mistakes and connections: Students try to build molecules like FI7 or Cl at the center with F5 incorrectly; the central atom must be the larger one, and only F, as the smallest halogen, surrounds. Shapes follow VSEPR with lone pairs: ClF3 has two lone pairs on Cl. Links to VSEPR, hypervalency and halogen reactivity.
T-shaped ClF3 with two lone pairs on chlorine, a strong fluorinating agent consistent with VSEPR theory. The interactive lesson shows this as a live animation or chart.
Chlorine trifluoride, ClF3, reacts vigorously with glass and most metals, showing its strong fluorinating power.
Compounds of two halogens such as ClF3 and IF7.
Interhalogen Compounds is a advanced topic in Inorganic Chemistry. It builds on beginner and intermediate topics, so review those first if needed.
Study these earlier topics in Inorganic Chemistry first: Halogen Reactivity Trend, Hydrogen Halides, Hydrofluoric Acid.
The next topics in Inorganic Chemistry are Oxoacids of Chlorine and Bleaching Powder.
Yes. The interactive lesson includes a self-check question on Interhalogen Compounds, and the Inorganic Chemistry quiz draws on every topic in this area.
Interhalogen Compounds is topic 48 of 113 in Inorganic Chemistry.