Problems Set - Meeting #7

1. Referring to the reaction carried out in the lab, answer the following questions.

a. Why is benzyne generated in-situ?

b. Benzyne is considered aromatic. Explain.

c. Which observations are made during the reaction?

d. How is the crude product purified? Which problems is the experimeter going to face here?

e. Which are the most intense peaks in the IR spectrum of the product?

2. A UV-Vis spectrum is also obtained for the compound obtained in this week's experiment.

a. Why does the procedure ask to use a quartz cuvette this time?

b. Which concentration is needed for the UV-Vis characterization of the TPN? How do you prepare this solution?

c. Why is it important that the entire sample dissolves when running a UV-Vis spectrum?

d.How do you explain the presence of the peaks in the UV-Vis spectrum of the product?

3. Donors and acceptors have a major influence on the reactivity of a diene or dienophile. Explain briefly why.

4. If the C-NMR spectrum of TPN is obtained at lower temperatures, the number of signals increases. Explain briefly.