1. General

Review the following topics: IR spectroscopy, polarimetry

Don't forget to start writing your formal report. By now, you should be able to write an introduction already.

2. Experiment

a. Jacobsen ligand

The potassium carbonate has to dissolve first before you can start adding the aldehyde. This is very important.

The aldehyde will be provided by the lab support. Please use only 1.0 g of it since it is very expensive ($5/g).

Make sure that you set the temperature to a gentle reflux and don't forget to stir it.

A reflux period of 45 minutes is usually sufficient in order to complete the reaction.

During the drying step, make sure that you follow the washing procedure correctly: first water, then saturated sodium chloride solution and last the drying agent in the organic layer only (try to remove the aqueous layer as good as possible).

For procedure how to use the polarimeter see link.

b. Synthesis of Ce(OH)₃(OOH)

It is very important to add the 30% hydrogen peroxide slowly otherwise the mixture will foam heavily.

Concentrated hydrogen peroxide is unstable and can decompose rapidly when in contact with transition metals and/or bases. It also reacts violently with certain organic compounds. Careful!

The filtered product needs to be washed thoroughly with water and then with acetone in order to remove the majority of the water. A dry product leads to better results in the oxidation.

3. Thing to think about

a. Why do you add water to the reaction mixture before you allow it to cool down?

b. How many signals do you expect to see in the ¹³C-NMR spectrum of the ligand?

c. How does the polarimetric measurement help to establish the absolute configuration and purity of the ligand?