Use resonance forms to show delocalization
of the negative charg...

Question

Use resonance forms to show delocalization of the negative charge in the Ruhemann's purple anion.

Accepted Answer

Hey everyone. Let's do this problem. It says from a list of resonance structures shown below, select all structures that contribute to the d localization of the negative charge in a derivative of the romans, purple and ion. So when we have resonance structures, those are created by the movement of pi electrons. Or sorry, a lone pair of electrons through the pi system. Or pi electrons in a benzene ring. Right. Being de localized around the ring. So let's start with structure number one. And apply either of those two situations and see if we get structures that are shown here in the answer choices. So first I can easily just move these pi electrons around the benzene ring and that would create structure number five. Right? Everything is the same except those electrons in the benzene ring. So then moving to structure number five. Well, I can move this lone pair of electrons from the oxygen. Those are congregated by this pi bond so they can swing down and create this chain of electron movement which will make the negative charge. Now end up on this oxygen instead. And if we look at our other structures that looks like structure number three. So let's go over destruction number three. Now that our lone pair is on the other oxygen? Well, I can move the pi electrons in my benzene ring once again To create another structure. And that will give structure number seven. Okay. And instruction number seven. Now that I've moved these pi bonds and moved the electrons as much as I could on this side. Let's see if I can move it to the other side of the structure. So we can move these electrons times with those arrows. Because all of these carbon bonds are conjugated with the pi system. So that will bring us to structure number two. Alright. And now we can rotate the benzene double bonds in this left hand Benzene 123. And that will give us structure number four. And now that we've rotated that benzene, let's see if we can move the lone pair of electrons again and we can moving them over to the other oxygen, Which leads us to structure # eight. And now let's rotate those benzene pi bonds one more time. 123. And that gives us structure number six. So, with all that being said, all of these structures are possible resonance structures for the romans, purple and ion, which makes d the correct answer for this problem. That's it for this one. I hope this video is helpful. And thanks for watching

Use resonance forms to show delocalization of the negative charge in the Ruhemann's purple anion.

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