Nitrogen does not interact with carbon to be leaving group?

[johnwandering]

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I was fairly confused about this problem:

Which is a more stable leaving group?:
A.) CH3-CN:
B.) CH3CH2SH


I thought that the answer would be A, because N is more electrophilic than S.
But the answer was B Because:

"Nitrogen does not interact with Carbon to be a leaving group."

I was wondering why is this exactly? What is it about N that exempts it from the broader laws of organic chemistry?

 

[gettheleadout]

I'm guessing it has something to do with nitrogen's smaller size and s-hybridization. Nitrogen isn't electrophilic either, as it wouldn't be attacked by a nucleophile if it were going to be a leaving group; it's pretty electronegative, but not significantly more than sulfur.

 

[dmf2682]

I would estimate that it has something to do with the reactivity of the nitrile which behaves similar to a carbonyl. Less reactive = better LG in my book.