Pyramidal inversion
Fluxional scientific equation / From Wikipedia, the free encyclopedia
In chemistry, pyramidal inversion (also umbrella inversion) is a fluxional process in compounds with a pyramidal molecule, such as ammonia (NH3) "turns inside out".[1][2] It is a rapid oscillation of the atom and substituents, the molecule or ion passing through a planar transition state.[3] For a compound that would otherwise be chiral due to a stereocenter, pyramidal inversion allows its enantiomers to racemize. The general phenomenon of pyramidal inversion applies to many types of molecules, including carbanions, amines, phosphines, arsines, stibines, and sulfoxides.[4][2]