-1
$\begingroup$

I read that chelate complexes generally are more stable than monodentate complexes. However, I noticed that in the case of $\ce{[Fe(CN)6]^3-}$ and $\ce{[Fe(en)3]^3+}$, this is not observed as the former is more stable. Why is this so?

$\endgroup$
2
2
$\begingroup$

Chelate complexes are more stable IF EVERYTHING ELSE IS THE SAME.

In your case, the anionic nature(cf. ethylenediamine is neutral) of cyanide makes cyanide a better sigma-donor than is ethylenediamine, while the pi-accepting nature(cf. ethylenediamine is pi-neutral, if not (hyperconjugative) pi-donating) of cyanide makes cyanide a better pi-acceptor than is ethylenediamine.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.