last updated Friday, October 10, 2003

Problems Set #6

ATTN: answers to the below questions are due at the start of your lab period of Meeting 6; these answers should be part of your pre-lab write-up.

The draft version of paper is due on 10-17-2003 at 5 pm in YH 1217. 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 you submit here, so more feedback you will get which will beneficial for the final version.

1. You are going to use TLC during the epoxidation experiment .

a. Which purpose does this TLC serve in this experiment?

b. You are going to use to different visualization techniques. In which sequence do you use them and why?

c. Sketch a TLC plate for the sample taken from the reaction after 30 minutes.

2. Referring to the epoxidation, answer the following questions.

a. Some of you will use N-pyridine oxide in addition to the catalyst. What is the function of this compound?

b. What is the source of the oxygen in the formation of the epoxide? Which other oxygen sources could you use with this catalyst?

c. Why do you use dichloromethane in this reaction?

d. Why is sodium phosphate solution used in this reaction?

e. A student only obtains 0.1 g of the catalyst. Can he still run the reaction? If so, what are the consequences for him?

3. Using Spartan, perform a PM3 calculation for Mn(salen)Cl and SalenH₂. How does the C=N-distance change as you go from SalenH₂ to Mn(salen)Cl? How could you detect the change using spectroscopic techniques available to you?