Problems Set - Meeting #7

1. The following questions refer to benzyne

a. why is it considered aromatic despite having 8p-electrons?

b. why is it formed in "in-situ" in this reaction?

2. Which of the following three reactions requires the mildest conditions? Draw the product.

R1: Cyclopentadiene + cyclohexene

R2: Acrylonitrile + butadiene

R3: 1,3-Cyclohexadiene + maleic anhydride

3. A student dissolves 0.5 g of tetraphenylcyclopentadienone and 0.3 g of anthranilic acid in 5 mL of tetrahydrofuran and then adds 0.6 mL of isopentyl nitrite.

a. How much carbon monoxide (in units of mL) is given off (assume reaction goes to completion) (Hint: CO might be treated as an ideal gas here!)?

b. Which size of flask would be appropriate for the reaction?

4. Why is the function of 1,2-dimethoxyethane in this reaction?

5. 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 and not a plastic cuvette like before?

b. What do you expect to change in the UV-Vis spectrum in comparison with last week's product?

c. Which concentration is needed for the UV-Vis characterization of the TPN?