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Meeting 15 (Acetyl Ferrocene)
Important Announcements:
1. Please look look for a partner for the last project (so far only 8 out of 34 groups signed up for a project!). Your partner should be in a different time slot than yourself i.e. if you are in T/R morning section, your partner should be in section in the T/R afternoon section or in the W/F afternoon section.
2. The proposal is due on February 26, 2010 at 4:30 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 proposal should not be longer than 4-5 pages and be submitted in a normal folder together with the important references. The entire folder will be returned on Monday, March 1, 2010. The proposal has to be submitted to turnitin.com as well (same course ID as before) by 10 pm on February 26, 2010, only one per group!
3. The next quiz (=quiz 6) will be administered on February 24, 2010 at 11 am. It will cover the esterification and nitration reaction. Make sure that you show up on time, which means that you have to be seated by 10:55 am. Otherwise you will not be allowed to take the quiz.
4. 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. The acylation lab will be on all next week.
Homework assignments (due February 23/24)
1. Referring to the synthesis of acetyl ferrocene, answer the following questions.
a. Identify the electrophile and the nucleophile in this reaction. How is the electrophile generated in the lab? Show a balanced chemical equation.
b. The electrophile produced in this reaction is a considered a weak electrophile. Which implications does this have for the reaction?
c. After the reaction is completed, the reaction mixture is poured into a solution of sodium acetate. Explain why. What should the student observe at this point?
d. Why is it important to "neutralize" the organic layer before performing the column chromatography step? Which pH-value is the student looking for here?
e. The crude product has to be purified by flash chromatography. What is the mobile phase here? What is the eluting sequence here?
f. The final product exhibits a melting point of 85 oC, while ferrocene melts at 174 oC despite being less polar than the product. Rationalize this observation.
g. The 1H-NMR spectrum of acetyl ferrocene exhibits four signals. Where are they located and what are the integrations?