Home > Community > Comparing reactivity of 1-chloroethane and 1-chloropropane in an SN1 reaction
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Minhsan Nguyen

Comparing reactivity of 1-chloroethane and 1-chloropropane in an SN1 reaction

David Shobe  Follow

Consider the following assumptions to somehow force these substrates to proceed for $\ce{S_N1}$ reaction mechanism:

  1. Low temperature

  2. Polar protic solvent

  3. Low concentration of nucleophile w.r.t. reactant

Now, in an $\ce{S_N1}$ reaction, the formation of carbocation is must.

The primary factor that determines the reactivity of organic substrates in an $\ce{S_N1}$reaction is the relative stability of the carbocation that is formed.$\ce{^1}$

According to your linked question: 1-propyl cation would likely be more stable than the ethyl cation.

Hence, your deduction that "the rate of reactivity towards $\ce{S_N1}$ will be greater for the second compound, i.e. $\ce{C3H7Cl}$" is correct.

P.S.: The 1-propyl cation can rearrange itself to a more stable 2$\pu{^o}$ carbocation, but that is not part of RDS to decide the reactivity order.

Reference

  1. Solomons, Fryhle, Snyder, 12E, Page 264

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Eugene Stavitskiy  Follow
@IamAlita (1) I concentrated on your question, not what asked in JEE paper recently. (2) The answers on the More
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Edward Atefi  Follow
linkedMore
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James Leland Harp  Follow
Which of the participants will be finished off first. Also, if I had to eat the More
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Haiping Li  Follow
You avoided all of my question and bounty description. I specifically asked about checking the 4. th step, and also, the second answer on that link contradicts your claim thermodynamically. How did you check the relative stability, that is the question.More
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Faisal M Saleem  Follow
propylium is more stable than ethylium, thermodynamicallyMore
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