0
$\begingroup$

I understand that ate complexes can result from the addition of carbanions to neutral aluminum alkyls.

I was wondering what the balanced equation for this reaction is/what the structure would be in solid state - like does it dimerize?

$$\ce{2 LiCH2CH3 + Al2(CH2CH3)6 -> ?}$$

$\endgroup$
2
$\begingroup$

The crystal structure of lithium tetraethylaluminate has been published (DOI) and as far as I can tell from the abstract, there is no indication for a dimeric anion here. It might be save to assume that the balanced equation therefore can be written as:

$\ce{2 LiCH2CH3 + Al2(CH2CH3)6 -> 2 Al(CH2CH3)4^{\delta-}\,Li^{\delta+}}$

| improve this answer | |
$\endgroup$
  • 1
    $\begingroup$ That is correct, but in solid state it forms chains of alternating Lithium and Aluminium, both in tetraedral coordination. (Separated by 7Å, hold together by van-der-Waals-Forces.) However, the paper refers to the compound as $\ce{LiAl(CH2CH3)4}$, but also suggest ionic character. They assume some electron density of $\ce{Al\bond{-}C}$ is shifted towards the Lithium forming a more centre bond with some covalent character. (I am just adding that because the question points to the sold state structure.) $\endgroup$ – Martin - マーチン Apr 16 '14 at 5:56
  • $\begingroup$ @Martin The -/+ added for clarity (and as separators) might indeed lead to wrong conclusions. I'll fix that. $\endgroup$ – Klaus-Dieter Warzecha Apr 16 '14 at 6:02

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.