Question

3. The table below summarizes the kinetic data for the following reaction at 4 k,(10-s) 100 24 21 16 1.0 0.24 0.21 0.16 CI NCS a) Based on the data, determine the reaction mechanism (dissociative or associative). Explain your answer (4 points) b) If the leaving ligand is not H20, but a bulkier ligand like P(CHs)s. Would the bulkier ligand favor this reaction pathway? Explain briefly. (3 points)

Answer 1

A. The reaction mechanism is associative as indicated from kinetic data. This reaction is SN2 second order reaction, first order with respect to complex formed and first order with respect to the base.

B. For SN2 displacement process, crowding is increased on complex, thus the intermediate is more strained than the complex and hence the reaction is difficult to occur.