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Meeting 15 (Acetyl Ferrocene)
Important Announcements:
1. The proposal is due on Friday, May 21, 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 5 (!) pages and be submitted in a report cover together with the important references. The entire folder will be returned starting on Monday, May 24, 2010. The proposal has to be submitted to turnitin.com as well (same course ID as before) by Friday, May 21, 2010 at 11:59 pm (only one per group)!
2. The last quiz (=quiz 7) will be administered on May 18, 2010 at 12 pm. It will cover the acylation reaction and metallocenes. Make sure that you show up on time, which means that you have to be seated by 11:55 am. Otherwise you will not be allowed to take the quiz. Students that provided responses that are exceeding word limit will receive a significant point deduction. The quizzes have asked for short and concise answers and not for random information in form of an essay.
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. The acylation lab will be on all next week.
4. The research project starts on Tuesday, May 25, 2010 and will extend through Friday May 28, 2010 at 5 pm. All NMR samples have to be submitted by then. There will be no chance to complete the characterization during the next week. Also, students will only be allowed to attend their own sections, which means that the work has to be coordinated between the students in the group.
5. Instead of dichloromethane, ethyl acetate will be used in the extraction procedure.
Homework assignments (due May 18/May 19)
1. Referring to the synthesis of acetyl ferrocene, answer the following questions.
a. The acylium ion is used as electrophile in this reaction. Why is it considered a weak electrophile?
b. How is the electrophile generated in the lab? Show a balanced chemical equation.
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. Which solvent is used for extraction here?
f. The crude product has to be purified by flash chromatography. What is the mobile phase here? What is the eluting sequence here?
g. How many signals does the 13C-NMR spectrum of acetyl ferrocene show? Rationalize their locations.
h. What are the characteristic peaks in the IR spectrum of acetyl ferrocene?