I am using a 3 liter cold finger sublimation apparatus to purify a metalorganic solid that is air-sensitive and water-sensitive. I use a
turbomolecular pump to achieve good vacuum. The heating mantle is heated up to approx. 100 deg C (for sublimation) and the sublimator head is cooled
down to approx. -10 deg C (for deposition/crystallization of final product).
Currently, I do batch sublimations, charging approx. 500 g crude material per batch. I would like to carry out sublimations of the material more
efficiently. Instead of adding more lab scale 3 liter units, I would like to scale up the current apparatus to handle 2-3 kg batches.
Any ideas or thoughts on this? The sublimation unit ideally must fit inside a glove box because the material is sensitive to air and the sublimation
is carried out in a glove box. The other consideration is that the crystals that form after sublimation+deposition must be uniformly distributed on
the cold finger/collection apparatus.
Thanks allhissingnoise - 27-12-2011 at 13:21
Can the compound be sublimed under an inert gas rather than reduced pressure?
And what *is* this fragile entity, pray tell?
Can the compound be sublimed under an inert gas rather than reduced pressure?
The sublimation is done in a glovebox, which maintains a nitrogen atmosphere; generally [O2] in the glovebox is always less than 1.0 ppm. The sublimation is done under vacuum
at moderate temperatures (opposed to standard pressure and high temps) because the material is unstable at high temperatures.
!