Which alkyl halide is more reactive in an SN2 reaction with a given nucleophile?
c.
d.
Verified Solution
This video solution was recommended by our tutors as helpful for the problem above
Video duration:
4m
Play a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
SN2 Mechanism
The SN2 (substitution nucleophilic bimolecular) mechanism involves a single concerted step where a nucleophile attacks an electrophile, resulting in the simultaneous displacement of a leaving group. This reaction is characterized by a backside attack, leading to inversion of configuration at the carbon center. The rate of the reaction depends on the concentration of both the nucleophile and the alkyl halide.
Steric hindrance refers to the crowding around a reactive site that can impede the approach of a nucleophile. In SN2 reactions, primary alkyl halides are more reactive than secondary or tertiary ones due to less steric hindrance. The presence of bulky groups around the electrophilic carbon can significantly slow down or prevent the reaction.
The ability of a leaving group to depart from the substrate is crucial in determining the reactivity of alkyl halides in SN2 reactions. Good leaving groups, such as iodide (I-) and bromide (Br-), stabilize the negative charge after leaving, facilitating the reaction. Conversely, poor leaving groups, like chloride (Cl-), hinder the reaction rate, making the choice of halide significant in predicting reactivity.