Announcements

1. The second quiz will be administered on Wednesday, January 20, 2010 at 11:00 am covering the ligand and catalyst synthesis and characterization. Bring a ruler, non-graphing calculator and blue or black pen with you. Please make sure that you arrive on time (this means that you should be seated by 10:55 am!!!). Late arrivals will not be allowed into the class room since they disturb the rest of the class!! This also means that you will not be allowed to take the quiz!!! The student is only allowed to write in the time slot permitted. This also applies to writing down the name. Failure to do so will be regarded as cheating.

2. The question below are due in your prelab for January 14 and January 15, 2010 (=meeting 4).

3. Starting this week, students will only be allowed to attend their own lab section. This means that you have to be better prepared when you come to the lab to get the work done in the allotted time, which is easily possible if you know what you understand what you are doing. If there are questions, you should ask them during office hours!

4. There is no data sharing unless permitted by the instructor. Everybody has to acquire her/his own spectra and data i.e. melting point, optical rotation. Students who share data will be reported to the Dean of Students since this is be considered cheating. This also means that the student name has to be denoted on the FTIR spectrum when the spectrum is acquired.

5. Make sure that you make progress on your formal report as well in terms of literature research and writing the parts that you completed already in the lab. The draft version of paper is due on January 29, 2010 at 4:30 pm. The draft version is worth 15 points, the final paper 45 points. For more information what the draft is supposed to contain see here. Late submission will receive less credit. The more of your work you submit in the draft, the more feedback you will get, which will beneficial for the final version. We will try to return the reports by Monday, February 1, 2010.

ATTN: Answers to the below questions are due at the start of your lab period; these answers should be part of your pre-lab write-up.

1. Referring to the synthesis and characterization of the Jacobsen catalyst, answer the following questions.

a. Initially the ligand is refluxed in 95% ethanol. Which purpose does this step serve?

b. The procedure recommends to crush the manganese(II) acetate prior to the addition to the ligand suspension. Explain briefly why.

c. What is used as oxidant in this reaction? How is it introduced to the reaction?

d. Like often in this lab course, the reaction will be monitored with TLC. Assuming the reaction is incomplete, sketch the TLC plate. What is the student looking for here? Which solvent does the Hanson paper suggest?

e. Why is the ethanol removed after the reaction is completed?

f. The drying agent is removed from the organic layer and heptane is added to the mixture. After removing a good amount of the solvent, some precipitate is formed which he isolates by filtration. However, he also observes that the filtrate is still very dark. What would you advise him to do?

g. One of the characteristic peaks for the catalyst in the FTIR spectrum is the n(C=N), which is shifted compared to the ligand. Where is the absorption for this group observed in the catalyst? How can the shift be rationalized?