ambident nucleophiles

[Andy Lechuga 2C]

Can someone explain how resonance is important with ambident nucleophiles. I don't understand how SCN- both N and S can act as nucleophiles. How can I look at it and understand which one is the nucleophile? I understand how it can be on both sides but I don't know why. Thank you!

[Rishi_Kayathi_1E]

Both N and S have a lone pair, so either can donate this to form a coordinate covalent bond.

[Da_Rhee_1O]

The definition of an ambident nucleophile is a nucleophile which can have more than one site by which they can donate electrons. This being said, Rishi is correct in saying that either the N or the S can donate. The resonance structure allows the flexibility in deciding whether the N or the S can donate.

[AngelaWang_1F]

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