Constitutional Isomers vs. Stereoisomers

alright, guys. So in the past we learned how to distinguish between molecules that were completely different, meaning that they didn't share molecular formula at all, or molecules that we called constitutional ice summers. And remember, those were molecules that had the same molecular formula, but they were connected differently. Well, it turns out that there's more types of ice summers than just that. There's also other types of ice MERS that have the same molecular formula that have the same connectivity. But they just simply have a different shape. The name of these types of ice summers is called stereo I summers, and that's gonna be the topic of this whole chapter. All right, so what I want to do at the very beginning, just to get started is go through these different types of ice tumors. Us can visualize these for yourself. Okay, so basically, we use ice swimmers to describe the relationships between similar molecules. We wouldn't even be talking about the concept of ice summers if it weren't for the fact that some molecules looked like they might be the same. And you want to analyze our this? Are they the same? Are they different? Okay, Well, it turns out that we can order these in in terms of the most different to the most similar. And the most different relationship that you could get between two molecules would actually just be different compounds. So that's what we're gonna fill in right here. I've given you guys examples like these before where we determine. Okay, I have two molecules, and I wanna know what's their relationship in this case, how would we figure that out? Remember that we use the flow chart that I gave you, and what I said is, Okay. First of all, how maney non hydrogen atoms does this have? Well, this one has five carbons, and this one has five carbons. Okay, so So far, so good. It seems like Okay, these are the same. These might be the same molecular formula, but then we talked about another, another category or another thing that we need to look at. And that's the I h. D. Or the index of hydrogen deficiency. Okay, Now, remember that the index of hydrogen deficiency had to do with rings, double bonds and triple bonds. So what would be the HD of this first molecule? Well, in this case, there's only one ring, so that means this would have a ni HD of one. Remember, What Aichi of one means is that we're missing two hydrogen. All right, Now let's look at the second one. The second one doesn't have any rings. It doesn't have any double bonds. It doesn't have any triple bonds. This wouldn't have an h d of zero. Okay, that means that this one is missing no hydrogen. Okay, this one is saturated. Okay, so I'm just gonna put that this one is saturated. Whereas the first one is missing two h is compared to the second one. Now, I just want to let you guys know if you're completely lost by what I just did. You've never seen this before in your life. Go back to the topic that is called I h. D. And I talk about how to figure out index of hydrogen deficiency with molecular formula and index of hygiene deficiency with a ah shape. Alright, So go back and look over that. It's about 20 minutes long and that will help you guys so much. All right. And then you might want to go over constitutional customers as Well, because that's what we're doing right now. Okay? So when we look at the relationship between these, what I want to do is I want to use this box to figure out what is shared between the two molecules. So, is the molecular formula shared? Actually, No. Because you think about it that the same amount of carbons, but they had different amounts of hydrogen, so they're different compounds. Okay. Is the connectivity the same? No, because they're different. They're different atoms, and the shape is also not the same. So basically, if your molecular formula is off, none of these other things can be shared because you're already messed up the first step, which is that they don't even have the same atoms. Does that make sense? So these would be different compounds.

So now let's go on to this next one. Okay? This next one, what I have is I'm trying to figure out the relationship. I see that this one has five carbons. This one has five carbons. And then I noticed that both of these have the same I h g. This one has an HD of one. And this one also has an HD of one. What does that mean? What that means is that these both have the same molecular formula. They both have the same amount of carbons on the same amount of hydrogen. So I would put a check mark that the molecular formula is shared. Okay, quote that. Now let's look at the connectivity. Are these connected in exactly the same way? Are all the atoms connected in exactly the same way? And the answer is no. Because in one of these I have a five member of ring and the other one I have a four member of ring. What that means is that these have different shapes and not just shapes. Thes have different connectivity is for example, this one right here has a tertiary carbon. Okay, And this one over on the five hammering on Lee has secondary carbons. Okay, so could these possibly be connected exactly the same? No, they're connected differently. So this is what we would call a constitutionalism. Er, okay. And just looking back, remember that a constitutionalism or would be something that has the same molecular formula, but different connectivity and obviously a different shape if it's not even connected the same.

I also want to this next example This next example. I'm gonna go ahead and count my carbons again. It's gonna be five. My carbons are gonna be five. I'll count my I h d. And that's gonna be one for this first one because I have a double bond, remember? Dull bond counts is one I'm going to do. I HD over here, and this is also going to count as one. So do these have the same molecular formula? Absolutely. They have the same number of carbons. Same number of hydrogen. Are they? Are they connected the same? Actually, Yes, they are. These have the same exact connectivity is well, because we have here is we have a double bond in both situations with a metal group on one side and an ethyl group on the other. Okay, in both situations, it's the same thing. I e I'm just gonna put an e t. Alright, So in both situations have the exact same Adams connected in the same exact way. So I'm gonna also put a check on connectivity. These have the same exact connectivity. Now the last thing is shaped. Do they have the same shape and the answer is no. Because if you'll notice this first one has a double bond in the orientation of Trans guys. Remember trances and trans. Okay, System has a trans double bond. Now, if I look at this other one and I draw my fence, I would say that my large groups are on the same side of the fence. Okay, so that means that this one assists. Okay, so what? That what does that mean? Does this have the same shape? No. Some means they have the same molecular formula. They have the same connectivity, but their shape is slightly different. So the name for this and you might have guessed it is stereo y summers. Okay. And like I said, this is the topic of this chapter. What I want you guys feel to do at the end of this chapter is able to distinguish with types of stereo customers. Name them, identify them, etcetera,

Finally, we get to our most similar compounds. Our most similar compounds would be something like this where I have the atoms of the same five and five. The HD for both of these would be zero. Got that? So far. So you have the same molecular formula. Are they connected the same way? Absolutely. They're both five carbon chains. These air, both plantains. Okay. Do they have the same shape? Actually, they do have the same shape, these air, all the same thing. And the reason is because check it out. This rotation here happened on a Sigma bond. Remember that? Sigma Bonds can freely rotate as much as they want. Okay, so all that happened was that I had to h is here, and I had a ch three here and afterwards that ch three flipped up and the two ages flipped down. Is that allowed to happen? Yeah, because this is a Sigma bond. Okay, so what do we call this? What's the relationship between these? Okay, these would be what we call conformers. Okay. Right. And conformers would just be that they basically have everything is exactly the same. Except that single bonds have rotated. Okay, notice that stereo I summers arm or different than conformers conformers are basically the same exact molecule, just a single bond rotated by itself. Whereas stereo I summers will always be different molecules. Okay, because stereo customers you can't enter convert between one and the other one is always gonna be stuck as one shape and the other one is always gonna be stuck is the other shape.