In this laboratory experiment we will use the known reactivity of the chromic acid
oxidizing agent, but instead of using CrO3 in a strong aqueous acid we will use it as a solid
supported reagent. The solid-support consists of a polymer resin that contains the active form of
CrO3. This Cr6+ modified resin effectively oxidizes appropriate substrates and has a few
experimental advantages. First, it avoids the need to use strong acid aqueous solutions.
Chemistry 283g- Experiment 3
3-3
Because the Cr is retained on the solid support it makes work-up of the reaction relatively simple,
and it makes recovery of the heavy-metal Cr byproduct trivial. Because this resin can also be
regenerated and reused, whereas the heavy metal products from the other simpler reactions are
usually discarded, this experiment also is a “Green” or more environmentally friendly reaction.
(The improper disposal of large quantities of so called “hexavalent chromium” (Cr6+) was the topic
of the movie “Erin Brockovich”).