Molecular dispersal was the process of disposing of matter through the dispersal of its component particles.
The Imperiatrix Pandora was dispersed for reshaping history to suit her wishes. The deed was thorough enough that memory of her was purged from history, though her existence was whispered in legend. Part of her consciousness managed to reform in the Matrix, and she attempted to take the position again during the Gallifreyan Civil War. (AUDIO: Imperiatrix)
Lord President Morbius was dispersed for attempting to conquer a large part of the galaxy with his followers. The deed was incomplete, though, since Morbius' brain was saved from dispersal, along with his consciousness. (TV: The Brain of Morbius)
The Fifth Doctor was sentenced to dispersal by the High Council as a means of preventing the return of Omega to N-Space. However, Omega managed to intercept the Doctor a split second before dispersal took place and deposit him in the Matrix instead. (TV: Arc of Infinity)
Zygon technology afforded molecular dispersal capabilities remotely. After Madra was killed, Broton dispersed the corpse in order to prevent it falling into the hands of UNIT. (TV: Terror of the Zygons) Similarily, a Zygon at the Lake District who had come to Earth on Brelarn's ship underwent molecular dispersal to prevent the Tenth Doctor and Martha Jones from studying it. (PROSE: Sting of the Zygons)