last updated Friday, February 22, 2008

Meeting 15 (Acetyl Ferrocene)

Important Announcements:

1. The proposal is due on February 29, 2008 at 5 pm in YH 3077 E (If you have problems please see me asap!). Late proposal will not be accepted and will lead to an automatic "F"-grade for the course. The important references have to be attached to the proposal. The proposal has to be submitted to turnitin.com as well (same course ID as before) by 11 pm on March 2, 2008, only one per group! Make sure that you have an electronic copy of your proposal with you. The computer lab is closed over Thanksgiving!

2. The next quiz (=quiz 6) will be administered on February 26, 2008 at 12 pm. It will cover the nitration reaction, Mass spectrometry and and the acylation reaction. Make sure that you show up on time. Otherwise you will not be allowed to take the quiz.

3. In the lab, you will only carry out the acylation of ferrocene, but not the synthesis of ferrocene. This part will be done individually and not in groups.

Homework assignments (due February 26/27, 2008)

1. Referring to the synthesis of acetyl ferrocene, answer the following questions.

a. How is the acylium ion generated in the lab? Show pertinent chemical equation(s).

b. The acylium ion is considered a weak electrophile compared to the nitronium ion. Rationalize the difference and explain which consequence this have for the Friedel-Crafts acylation.

c. Which compounds does the reaction mixture contain after the completion of the reaction?

d. Why is it important to "neutralize" the organic layer before performing the column chromatography step?

e. Why is petroleum ether used in the beginning of the elution process and a mixture of petroleum ether and ethyl acetate later on?

f. What would happen if the student were to uses a solvent mixture of 50:50 for the elution?

g. The ¹H-NMR spectrum of acetyl ferrocene exhibits three signals at from d = 4-5 ppm. Rationalize this observation.

h. A student reacts acetyl ferrocene with phenyl hydrazine. Which product is formed? In which way does this reaction help to verify the identity of acetyl ferrocene?