Thin Layer and Column Chromatography
Experimental Procedure for Part 3: Purification of Ferrocene by
Sublimation
1.
Evaporate the solvent from the yellow ferrocene solution
under vacuum. Use a steam bath if heat is required.
2.
Determine the weight of the ferrocene residue.
3.
To sublime the ferrocene residue, see Figure 2 in “Figures for
Column Chromatography and Sublimation” under Resources.
Push a centrifuge tube through a black neoprene adapter.
Place it and the centrifuge tube into the mouth of the flask
with contains the ferrocene.
4.
Place the apparatus in a thermowell and clamp it so that the
bottom of the flask is touching the sides of the thermowell.
Attach the side-arm of the flask to the vacuum with black
rubber tubing.
5.
Turn on the vacuum. Next, fill the centrifuge tube with pieces
of ice, so that the centrifuge tube becomes a “cold finger.”
Finally, turn on the thermowell to a high setting.
6.
Watch as the ferrocene sublimes onto the surface of the cold
finger and the upper sides of the flask. When the bottom of
the side-arm flask is empty of solid material, wrap the sides
in aluminum foil so that all the ferrocene collects on the cold
finger.
7.
Turn off the thermowell, then the vacuum. Very slowly and
carefully disconnect the rubber hose from the side-arm (a
blast of air can knock the sublimate off the cold finger!)
8.
Carefully, remove the centrifuge tube from the flask. Scrape
the ferrocene off the tube and onto tared weighing paper.
Record the weight. Take a melting point of the purified
compound.
9.
Evaporate the solvent from the acetylferrocene orange
solution by heating the flask on a steam bath. Obtain the
weight and melting point of the acetylferrocene.