Canonical structures of (1E)-prop-1-en-1-yl acetate

Question

I have to find all of the possible canonical structures of this molecule

And here's what I did

Are they correct and if yes, did I miss any possibility?

These are correct, and I see one more fully octet structure that is closely related to a non-octet structure. — jerepierre, Mar 23 '16 at 19:48
No, in that drawing oxygen has 10 electrons. I would only draw two, to be honest. You're already delocalising a lone-pair on oxygen in one direction. You could also delocalise it in the other direction. — , Mar 23 '16 at 19:56
That structure isn't possible... Sort of on the right track though. Think more about what you have on the bottom line and apply it to the top line. — jerepierre, Mar 23 '16 at 19:57
If oxygen is neutral in the last structure you drew, it would still have 10 electrons. We only observe elements capable of an extended octet in the 3rd period. However, if it has 8 electrons, its charge would be 2+. Oxygen is very electronegative, so that doesn't sound so likely, right?
I will post a more detailed answer, or at least resources, a bit later. Meanwhile, please edit your post, so that it doesn't look confusing to someone new coming in. As you did in your original post :-)! — , Mar 23 '16 at 20:58
It is correct, the oxygen in the last structure has 8 electrons and one positive charge on it. No idea how 3 bonds and 1 lone pair will add to 10 in other comments. — Coconut, Mar 23 '16 at 21:21
No I took it away, there was an oxygen making four bonds and having one lone pair. — p-bromonitrobenzene, Mar 23 '16 at 21:39
If my oxygen makes 4 bonds and has one lone pair, is it neutral? — p-bromonitrobenzene, Mar 23 '16 at 21:40
I just did it again and I changed the results in the question so please take a look and tell me if something is wrong. — p-bromonitrobenzene, Mar 23 '16 at 22:17

score 1 · Answer 1 · answered Mar 23 '16 at 23:06

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May it look like this? In those two possibles ways?

answered Mar 23 '16 at 23:06

p-bromonitrobenzene

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Your top row is not possible. Look at the last three rows: there are octet violations – Ben Norris Mar 24 '16 at 01:23
I don't see how. – p-bromonitrobenzene Mar 24 '16 at 01:29
And I have done the same things in the bottom row – p-bromonitrobenzene Mar 24 '16 at 01:30
Oh, you are correct! You have an octet rule violation in the bottom row also. – Ben Norris Mar 24 '16 at 01:32
But how? Is it because of the triple bond of the oxygen? – p-bromonitrobenzene Mar 24 '16 at 01:33
On your image, you have two structures with oxygen atoms that have one double bond, one single bond and two lone pairs = 10 electrons. You also have two structures with oxygen atoms that have two double bonds and one lone pair = 10 electrons. – Ben Norris Mar 24 '16 at 01:40
So the oxygen with one double bond and a single bond should have one lone pair and the oxygen with two double bonds should have none? – p-bromonitrobenzene Mar 24 '16 at 01:46
And the formal charges work. For the oxygen with one double bond, one single bond and two pairs it really have a charge of -1 since 6-3-4=-1 – p-bromonitrobenzene Mar 24 '16 at 02:01
You have also missed one along the allyl ether moiety – Beerhunter Mar 25 '16 at 11:04

Canonical structures of (1E)-prop-1-en-1-yl acetate

1 Answers1