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Organic Chemistry

Learn the toughest concepts covered in Organic Chemistry with step-by-step video tutorials and practice problems by world-class tutors.

2. Molecular Representations

Functional Groups

We can group millions of different molecules into families of similar functionality.

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concept

Why we need functional groups.

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Alright, guys. So in the next few videos, I want to go over probably the most important concept of this chapter which is recognizing functional groups. Now, I know that you've all heard of this before, that you're gonna have to memorize some stuff you're gonna have to memorize. What's, um, molecules look like? Hopefully a few of you guys know some of these names from Gen camp, but regardless, it's gonna be fine. I'm gonna give you guys enough practice that by the end of today, you're gonna feel pretty confident with these groups. All right, so let's go ahead and get started. So what is the entire concept of functional groups? It turns out that before functional groups were categorized, what was happening is that scientists were literally just finding out finding out new molecules and they naming them after whatever they wanted. So they named them after their cat. They named them after their girlfriend. They break up with their girlfriend, and that doesn't even make sense anymore. And it was terrible. Basically, they had these entire books of just millions of molecules that just had these random names. And you can imagine that if you hate chemistry. Now, er, if you think it's challenging back, then even sucked way worse. So they decided. OK, early 19 hundreds. Let's actually make groups out of this. Let's let's figure out what these molecules do. Let's figure out if they do similar things, that we can group them together into similar sets of molecules. So now instead of me teaching you like 1000 different names, I'm only gonna teach you like 10 14. Something like that, depending on how many you need to know for your book. That's how many I'm gonna teach you. All right, So isn't that a lot better? Guys ready to start? Cool. So what we what we group them into is groups of similar functionality. So go ahead and write that down. That just means, um we group them into what they do. Okay, so there's certain types of molecules that they just all do the same thing or they all react in very similar ways. And that's how we group the
Hydrocarbons
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Recognizing different types of hydrocarbons.

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So let's go ahead and start off with hydrocarbons, Okay? We've talked about hydro hydrocarbons before, and these would be your single bonds, double bonds and triple bonds. Okay? There's actually more types of hydrocarbons than that, but these the ones I want to focus on right now. Okay, so we've been calling them single double triple. Now what I want you guys to refer them at us to as is Al Keynes, Al Canes and all kinds. The reason is because a double bond could exist between lots of different atoms. It could be a nitrogen nitrogen, double bond. That's not the same. So if you have a carbon carbon double bond, you should be more specific. And you should say that that is an AL Keen. In case you could tell, all that's changing is really one letter A e y. Okay, so, as you get further in the alphabet, you're adding more bonds. Not too bad. So I want to just say a few things about carbon structures before we get into a lot of functional groups. Because if you understand the carbon structures really well, the other one is gonna be easy. First of all, it turns out that all carbon groups, regardless of their size, can be symbolized using what's called in our group. Okay, this is something that we use every single day in or go. All it means is this your our group is part of my French, the I don't give a shit about this part group. Okay? It means that you have a particular part of the molecule that you're focusing on and everything else that you don't really care about, especially if there's a big molecule. If you're just going to say that's a are OK, that's just means it's a carbon group, that it could be 100 carbons long. I don't care about that part of the molecule. I'm just gonna write in our instead. Cool. We use that literally every single day in or go. All right, Um, when an Al Cane is this is so this is a separate thing. When Al Kane is attached to a greater carbon chain, it's given a Y l. Suffolk's Okay, So what that means is that an Al cane, if it's a branch off of a bigger chain, it actually becomes an Al khial. Okay, so here have shown you an example where I have a six carbon chain with a one carbon branch coming off of it. The biggest chain is gonna be referred to as the Al Cane, whereas the smaller branches gonna be referred to as the alcohol. Okay, so that's something to keep in mind that you put that y el whenever it's a branch, okay?
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  • All carbon groups regardless of size can be symbolized using an –R group.
  • When an alkane is attached to a greater carbon chain, it is given a –yl suffix
    • An alkane turns into an alkyl group.  
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How to assign degrees to carbons and hydrogens.

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So then, lastly, we have to figure out giving degrees for carbon and hydrogen. Okay. And degrees just have to do with how many other things are attached to my object or to my target. Okay, so the carbon here is given a degree based on how many other carbons they're attached to. Okay, so what I do here is I say that not all carbons are the same. I care. I'm going to differentiate my carbons based on how many other carbons they're attached to. Okay, so I'm going to show you an example of that in a second. So basically the words that we use for that our primary secondary tertiary and Quaternary or these little degree symbols. All that means is it tells you how many other carbons are directly attached to that carbon. Okay, then hydrogen. Because hydrogen always have one bond. Remember that hydrogen are Onley happy with one. Whereas carbons can have a lot of different. They could have. They always have four bonds, but they could have been bonded to other things besides carbon. Okay, so hydrogen are just going to possess the same degree as the carbon that they're attached to. So What that means is, if I have a tertiary carbon, that means it's attached to three other carbons. The hydrogen that's on that tertiary carbon would be called a tertiary hydrogen as well, because it's a hydrogen of a tertiary carbon. Does that make sense? So what? I want us to dio. I know that's kind of a lot to take in. I have these five circles. I want you guys to identify one at a time. What types? What degrees of hydrogen and carbons we're dealing with in this molecule that's gonna help a lot for the next page of functional groups.
  • Carbons are given a “degree” based on how many other carbons they are attached to.
    • Degrees are expressed as primary, secondary, tertiary and quaternary (1o, 2o, 3o, 4o)
    • Hydrogens possess the SAME degree as the carbon they are attached to 
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Determine the degree of the indicated carbons and hydrogens.

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So, for example, let's go ahead and start off with this age. Actually, you know what? Let's not start with age to start with carbon. Let's start off with this carbon. What type of carbon is that? The answer is that it's a primary carbon. Why is that? Because it's on Lea attached toe. One other Adam and that's a carbon. And actually, I kind of said that wrong. It's only touched toe, one other carbon. That's the biggest thing. Okay, so let's move on to this. A trait there. What type of h is that? So this age is what we call a tertiary hydrogen. Okay, The reason is because the hydrogen is attached to a carbon and I get the degree from the carbon is attached to, and that carbon is attached to three other carbons. 123 Okay, so that means that that would be a tertiary hydrant puts on a tertiary carbon. All right, let's move on. How about this bottom carbon down there? What would that be? So this would be a secondary carbon. Okay. Why? Because it's attached to two other carbon groups. Okay, what about this carbon right there? That would be what we call a Quaternary Carbon Co ordinary carbon means that all four of its bonds are single bonds to carbon. Cool. And then finally, what about this last one that I wanted to start with? This would be a primary hydrogen. Okay, Why primary? Because it's attached to a carbon that is attached toe on Lee. One other Cartman, see how that works. It's a little bit tricky. I could tell. Ah, lot of you guys thought that was gonna be a co ordinary cart co ordinary hydrogen. But that is not a co ordinary because it's not directly coming off of the ordinary carbon. Okay, it's a primary because it's coming off of a carbon, that red one that is only attached toe one other carbon. Okay, does that make sense? So it turns out that as we learn more functional groups, I'm going to teach you that as we name degrees for them. Some of them are gonna be named as hydrogen, meaning that some of them are gonna have the same degree as they would if they were hydrogen. And some of them are gonna have the same degree that they would as if they were carbons, and it's important for you guys to remember that distinction. That is one of the things that tricks people the most in functional groups, and I'm gonna teach it to you. But I'm just giving you a heads up. You need to think in terms of hydrogen and carbons that the other functional groups will make sense to you. All right, so with that said, let's go ahead and move on to the next page.
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Alkyl Halides
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Recognizing alkyl halides.

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So our next functional group is the alcohol. Hey, lied. And the alcohol. I really tells you what it is, right at the beginning, alcohol has to do with carbon. So that would be in our Remember that I said our could be used for any carbon group. And hey, lied is a halogen. So I remember that the letter that we used for halogen is X. So the abbreviation for an alcohol Haley is our ex. Anytime you see Rx, we're talking about an alcohol hate light. Okay, so, like I say right here, it's any our group that's a directly attached to a halogen ocular. Hey, Light. This is a very important functional group for or go one especially, and the degree of the alcohol. Because remember, I told you were talking about degrees here is gonna be determined the same way as a hydrogen. Okay, so remember, how did we determine degrees with hydrogen? We would look at the carbon it's attached to and say, How many other carbons is it attached to? Okay, so here I have three different alcohol highlights for you. You could tell these air all carbon groups. I'm gonna call this one a B and C thes air. All halogen is directly attached. Are. And now what I want you guys to do is tell me if their primary secondary or tertiary. Okay, so go ahead and look at the first one. Tell me, what do you guys think?
  • Condensed Structure = -RX
  • The degree of the alkyl halide is determined the same exact way as hydrogen. 
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Assigning Degrees to Alkyl Halides

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so the way we were determined, as I look at the carbon that is attached when I say how many other carbons is it attached to one? So this is gonna be a primary. Al Kyohei lied. Okay, so now let's look at the second one. B. What kind of alcohol it is that that's gonna be a tertiary alcohol, Haley. Why? Because I look at the carbon it's attached to. And I say, how many other carbons is it attached to? 123 tertiary. Okay, lastly, we have let her see. Go ahead and figure out if that which one that is. So this one would be secondary. Ocular. Hey, light. Okay. The reason is because, my bro mean is attached to a carbon that has three bonds. But only two of them are two carbons. That was the thing that might have gotten you a little bit tripped up. Maybe you said tertiary because you forgot that this is a hydrogen. Hydrogen is don't count. All I look at is how many other carbons is that carbon attached, you see? So this is actually not that hard. Once you learn how to do it for hydrogen, aka highlights or the same exact thing. Now what's cool is that by naming the degree we actually group these together in terms of their functionality. It turns out that primary alcohol slides react in a much different way from tertiary alcohol highlights. And by grouping them like this, we can actually have very predictable reactions that we can run based on saying Okay, we want a primary here. We want to tertiary there, it's gonna change it.
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Functional Groups without Carbonyls

Carbonyls are C=O bonds within a molecule. First we’ll learn about common functional groups that don’t contain these.  

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How to recognize alcohols, amines and ethers.

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So for the next six functional groups, what I want to do is I want to kind of clarify something. Have you guys heard this word? Carbon? Neil? Maybe your professor calls it Carbonnel. Totally fine. However you want to say it, that's fine. In fact, you're probably going to notice this semester that I'm going to say some things very different from the way you're. Professor says it may, because Professor speaks a different language, mostly as a first language. Or also just because, you know, people have different ways of saying these molecules. Okay, but so I'm just gonna say Carbonell Carbon Neil looks like this. It's a C double bond. Oh, okay. Anna Carbonell is not a functional group, okay? It is only a component of many functional groups. So if I say the word Carbonell, that doesn't mean that that's a functional group. It just means that's a part of the functional group. Okay, so I'm gonna go ahead and talk first about functional groups without carbon eels, and then we're gonna add some carbon deals and see how that changes them. Okay, so the first one not first Sorry. The third one that we're gonna talk about today is alcohol's alcohols are defined as r. O H any carbon group that's attached to an O. H. And there's lots of different alcohols. But the important thing to know is that the way that you named the degree on them is the same as H is once again. Okay, so now we know that alcohol. Hey, lights and alcohols are both named exactly the same in terms of degrees. Okay, so here I haven't alcohol for you. Please don't try to drink this alcohol. This would probably kill you. OK, The only alcohol that's safe for drinking is ethanol. Even if you just take off one carbon to make methanol, it's toxic. 50 g of that in your dead. Okay, so So they're not all fun and games. Okay? We actually used these in the lab a lot. So what type of alcohol would this be, though? What do you guys think? So it's attached toe one carbon. That that's fine. Remember that We say that you always look at the carbon that that carbon is attached to. That carbon is attached. Onley one carbon. Okay, this is the same as hydrogen. So this is gonna be a primary alcohol, okay? And that's how we categorize it. All right, I'm gonna give you guys more practice with this later. Okay? Then let's talk about the next functional group A means Okay, so it means the way that they work is that they actually have carbon groups directly attached to the end. Which means that there's a lot of different types of means that you could have one of the most common would just be having end h three. Okay, that's the type of a mean. But if you add our groups to it, that's also to me. And so if I had r N H two that is also in a mean If I switched out hydrogen for ours, that will still be in a mean. So then let's say that I had are two n h. That just means I'm taking one of the h is and I'm replacing with the R. And then finally I could even have are three. And and that would also all of these would be types of a means. Okay, as long as basically it is a carbon group carbon or hydrogen attached to a nitrogen. That would be in a mean. Okay, So what I want to do here is talk about the degrees. Okay. This is an example of an amine. Anytime you see, just a nitrogen single bonded, two carbons. You're in. Good luck. That's Inamine. Alright. The way that we Oh man. So I just realized that their typos here. So I'm gonna go ahead and scratch those out. Okay? The degree of the amine and the degree of the amad. Sorry about that. Okay. So go ahead and scraps those out. Sorry, my bad. But the degree of the amine is actually determined the same way as carbon. Okay, so in this case, that's why I have a star next to it. Because I want you guys to remember this. This trips everyone up where they think that the amine is named like the alcohol. Hey, lie or whatever. So you get them mixed up. So what that means is that the primary secondary tertiary is based on how maney carbons are directly attached to the end, not to the carbon that's attached to the end. So in this case, what type of a mean? Would this be right here? This ring structure What kind of a mean, This would be a secondary amine. Okay? And the reason is because the end is directly attached toe carbons. So this one is basically considered, like a carbon instead of like a hydrogen. Alright, keep that in mind, and that's a huge distinction. Okay, then finally we have ether. Okay? Ether is abbreviated. Are oh, are an easy way that I always remembered. It is I'm an ether roar. That was awkward, right? So anyway, I'm an ether. Your skerry blow up either is actually do blow up, so maybe that helps you remember? All it is is an oxygen in between two carbon groups. Okay? And honestly, we don't need to name degrees for these because there's only one type. So that's it. Just remember r o r. And you're good to go
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  • Alcohol Condensed Structure = -ROH
  • Amine Condensed Structure = -NH3, RNH2, R2NH, R3N
  • Ether Condensed Structure = ROR

These three functional groups completely change when they have a carbonyl next to them!

Functional Groups with Carbonyls
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How to recognize carboxylic acids, amides and esters.

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now what I want to do is I wanna add carbon kneels next to all of these and see how that changes them. So I'm gonna add a carbon Neil to my alcohol. I'm gonna add a carbonell to Maya mean, and I'm gonna add a carbon Neil to my ether. And I'm gonna show you guys how that changes the function Functional group. So if I add a carbon, you'll to my alcohol That means what it's gonna look like is now see double bond o with an O. H next to it. Do I see that? So basically, I'm taking the o. H. From here on, I'm just adding it next to my Carbonell. Alright. It turns out that this is going to react way different from a regular alcohol because that carbon you'll and we're actually gonna find out a lot more about that in the acids and bases chapter. Okay, So what that means is that, um, this is gonna turn into called a carb oxalic acid. This is the main acid of organic chemistry. So most of the assets that we deal with a lot of them are car oxalic acids. And what I'm gonna do for these. I'm gonna also show you guys the condensed form of writing it because this is very common. So the way that it's written is as c o. H. So if you see C o h, that's to do with car oxalic acid. Another way that it's written. It's C O to h. Okay, these are condensed abbreviations that confused a lot of students. So it's important that you guys keep in your memory. This is the memorization part. It's important that you guys memorize that C O. H is a car oxalic acid. It makes sense just by looking at it. C o h. But still you need toe. Just make sure you know it. Then we've got so basically alcohol plus a carbon deal, you got a car oxalic acid. Then let's do in a mean plus a carbon. You. Well, in this case, what I would get is I would get my carbon Neil and then I would add N h two next to it. Okay, so I'm just taking my amine from here, and I'm adding it here. All right, Well, the condensed formula for this is gonna be C o NH two or whatever that however many h is that nitrogen has And this is going to go from being in a mean, That's what we call either you could call it a meid or Amad. Okay, both. I've heard both pronunciations several times from different professors. I say Amad, but there will be some ways. Sometimes I'll even say in mind. It just depends on what's in front of it. Sometimes if the name is really long, it sounds better to say in mind. All right. So whatever I'm just trying to say, Don't be strict out the pronunciation. Just be strict about knowing what it is. Okay, so that's kind of easy Notice that I go from a mean I add a carbon deal and it goes to and image easy. Okay, the degree of the AM, it is determined the same way as a carbon. Okay, so if I gave you the following Amit, Okay, this is actually gonna be Yeah, I'll give you that, Amon. Okay, What type of amad with that beef? So this is actually what's called a cyclic amp cyclic amad. And later on in or go to, we're gonna learn that these are very important it gets the name of a lack tan. Okay, so now I'm totally just jumping ahead just to make this interesting. Okay? You do not need to know about lack Tam's yet, but I just want you guys to know that I lacked him is a type of amad. And what's the degree of it? What would what would be the degree of this amad? It would also be secondary amad so you could call it elect him or you call a secondary amad. Why? Because this nitrogen here is attached to two carbon groups. See how that works? So it's just the same as we were using for them. Mean on also the same as we're using for carbon Cool. And then you got this Last one will try to move out of the way a little bit. So we've got Esther. Esther is what forms when you add a carbon Neil and then you just take the O. R. From the ether group. Okay, So isn't that cool we get when you have taken a mean at a carbonell turns to in a mind ether. Plus the carbon eel turns into an Esther. So these names are very similar, And that's one of the ways that helps to remember You could just say, hey at a carbon deal on it becomes the one that sounds like it. So in Esther, the functional group is gonna be or the condensed formula is gonna be C O R. Okay. Anytime you see C o R. That is an Esther, there's nothing else that you really need to know about this also, it could be C 02 are okay, but other than that, I just want you to be able to recognize thes.
Content
  • Carboxylic Acid Condensed Structure = -COOH
  • Amide Condensed Structure = -CONH2
  • Ester Condensed Structure = -COOR

As you see, these functional groups are similar to the other ones, but have different names due to the adjacent carbonyl. 

Adding Carbonyls to Hydrocarbons
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The difference between aldehydes and ketones.

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So now let's talk about strict Carbonell groups. These were going to be groups that these are gonna be carbon. You'll see Delavan. Those that do not have oxygen's next to them. Nitrogen is next to them. Stuff like that. All they have is carbons, Okay? And in that case, it's still not appropriate to call them carbon Neil. Instead, we're going to use the words or the names ketone and Alba hide. Okay, so what I'm gonna do here is gonna give you guys the explanation of the difference between them. Because a lot of students get stuck on What's a key tone? What's an alga high? All right, so I'm just going to show you guys really quick. A key tone is gonna be a carbon Neil that has to our groups on both sides. Okay. Whereas an alga hide is gonna have one or more. H is on one of the sides. Okay, So right there, there's the difference. And Alba hide is gonna have an H. Whereas a key tone will never have an H directly coming off of the carbon. You okay, But another way that I like to think about these because I think it helps is if you're looking just at a structure like I have right here, just like a really big structure. Another way that I want to think of it is that a key tone is an internal carbonell group, whereas an Alba hide is a terminal Carbondale group. Now, what are these words? Internal in terminal. Their location words. They're actually words that we use a lot in or go. It means is something in the middle of a chain or of a ring or something at the very end? Okay. And you can guess that terminal would be the end. So here what I have is I have three carbon eels, okay? And instead of thinking of H is and ours, we could think about internal and Terminal. So right away, how many of these carbon eels are terminal? Meaning that they that they are on the very last carbon off whatever chain there on and the answer is, two of them are terminal. This one is terminal because it's at the end of that long chain, and this one is actually also terminal cuts at the end of that branch. Does that make sense? Both of these also have in h That's not drawn. Okay, if they both have an h that's not drawn what types of carbon nails are these Alba hides is not cool. So I really don't care which definition you use. I'm just trying to give you guys multiple ways of thinking about it, All right? But I Ah, lot of times I used to it confused which one was which. And then I started just thinking Alba hides on the end. I would always say that Aldo hides on the end, and that would help me. All right, so lastly, what about this Carbonell here? This one's not terminal because it has more has an r group right there. So has more carbon coming off of one of the sides. So basically, this carbon would be this carbon. It would be internal, could surrounded by carbon on both sides. So this would be my only key tone on this molecule. Alright, so I've got my key tone. I've got my alga hides learn to recognize them. I'll give you guys practice with this. Now notice that these air Onley, ketones and alcohols IEDs because they don't have other types of Adams next them. If they had an oxygen or if they had nitrogen, then they would become the other functions that we talked about, like am IDs and stuff like that.
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How to write the condensed structures for aldehydes and ketones.

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So now I want to talk about the condemned structures, So the condensed abbreviations for these can be a little bit confusing. So for key tone, it's actually just gonna be. And so this could get this can get confusing. Sometimes it's gonna be see. Oh, see? Okay. And what that means is that sometimes your professor is gonna be nice enough and give you see dull. Bon O c. Okay, that means that kind of helps you that this is a carbon. You'll okay, but sometimes they're just going to say C O c. And they're gonna expect you to know that this is a that there's a double bond. Oh, in between. Okay, now some you guys must be wondering. Well, how is that different from a f from an ether, then? Because an ether is r o r. Remember, How is C o. C different from our own are because remember that if it was an ether, ether would be ch two. Oh, ch two and then the rest of the art group are here and are here. Notice that both of those carbons would have to h is coming off of them. Okay. Whereas for the carbon right here. That carbon is never gonna have h is coming off of it. So that means that the our group is gonna be directly attached to a carbon that does not have any hydrogen on it. So basically, the carbon that I'm looking at is right here. I tried to use a different color. That carbon right there is never gonna have hydrogen. So that's the difference. Instead of saying, C h 20 is just gonna say CEO. And when you see the CEO that told you this is a key tone and not out and not a and not an ether, this would be either down here, by the way, not trying to confuse you, that would be our our would be an ether. Okay, So, like I said, I'm kind of going above and beyond here. Hopefully, your professor gives it to you like this. If they give it to you like that, then we're fine because you have the job on there. It's very easy. But if they give it to you like this, then you need to look at the fact that it's C o. Meaning. See? Double bond. Oh, all right. Awesome. So then finally, alga hide kind of sucks to the abbreviation for alga hide. It is probably one of the worst ones in organic chemistry, and it's C H. O. Okay. How does that make sense? I do not even know. I think of it like a choo choo train like it's Chou. Alright, so there's really not a good way to memorize Thio. Remember it other than just to memorize it. I still have students in or go to that will forget that C H o is an alga high. So I would just say, committed to memory, make sure you don't get confused. All right, make sure that you just like, give extra special attention to Al hides.
  • Ketone Condensed Structure = -COR
  • AldehydeCondensed Structure = -CHO

These condensed structures aren’t very obvious. So just apply them to memory!

Nitriles
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How to recognize nitriles.

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So night trial. This is This is a functional group that I really never have problems teaching because it's so weird. Basically, it's so much different from the others. It's just gonna be see Triple Bond n It starts with N, and it has an Internet. So it's a night trial, and the abbreviation for this in condensed formula is just CN Okay, so that makes it really easy. If you ccn, that just means see trouble Bond n.
Content
  • Nitrile Condensed Structure = -CN
Aromatic Hydrocarbons
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The difference between phenyl and benzyl groups.

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then finally, we have benzene. I've been avoiding benzene for a while now. I haven't really talked a lot about it, but now I wanna I wanna give it some attention. So bending is a type of aromatic compound. Okay, we will not learn about aromatic compounds until or go to, so I'm not going to explain what that means. I'm just gonna ask you to know that that exists, okay? That's when we actually get to the fun stuff in or go to write. But for right now, just know, be able to recognize it and actually has two different names when it's a branch on a larger chain. Okay, if it's just by itself, like the clutch logo. Okay, If you just see it by itself, that's Benzie. Just say that that's benzene, or you can also call it aromatic. But when it's on part of a larger chain, it gets its own types of branch names. So, for example, when it's directly attached to a our group, the name doesn't isn't bending anymore. It turns into fennel okay, And fennel indicates that I have a benzene directly coming off of a chain. The way that we write in condensed formula. A lot of times, it's as C six h six. Okay, I'm sorry I messed that one up to see such six h five. Okay, because it has one hydrogen missing because directly attached to a large our group. Okay? And then also, it could be abbreviated as p h. Okay, But this isn't the ph that you saw in acid in bases where you have, like, ah, lower case p in a big H. This is like both of them are lower case. Okay, Cool. And then if there happens to be an extra ch two group, um, just like in between the benzene and the ring, Then it gets even a different name. And that name is Benzel. Okay, Now, this one to me is counterintuitive. Because if I were writing organic chemistry from the very beginning and I saw a benzene group on a chain, I would say, Oh, that's a benzel group, because alcohol, alcohol, like al cane alcohol. So I would say benzene, benzel. That makes sense. But it turns out that for some reason, they decided to name the one directly attached to it as fennel. And the one that's one carbon away as Benzel. So it's kind of flipped from what you would think. That's why I want to point out that Benzel is always has that CH two in the middle the way that we would abbreviate it is as ch two c six h five. So notice that there's that CH two in there and then it's also abbreviated as bien. Okay, not often, but I have seen that before, So I got this long chain with to bend genes on it, and I want you guys to tell me which one is the fennel? Which one's the Benzel. So go ahead and look at it for a second and then let me know. So this one would be the fennel because it's directly attached right here. And then this one would be the Benzel because it has one carbon in the middle. It has an extra C H. Two. Does that make sense? So that's a benzel on a fennel, and that's the way we're gonna use them when we're naming benzene on rings
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Identifying Functional Groups

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So what I want to do is just a worked example just between you and me. Free response. Go ahead and try to identify all the functional groups in this molecule. So, first I'll tell me how many functional groups are there? Is it three? Is it five? Is it seven? Go ahead and tell me. Then go ahead and try to identify each one. And if applicable, tell me what the degrees are. So tell me if it's gonna mean tell me that it's secondary or whatever. So go ahead and try to do that. Pause the video, and then let's go ahead and talk about how many function groups and what they are. All right, so that was a little tricky. I think that it was even more tricky because I gave you some condensed formula in there, so it kind of threw you off a little bit. Students typically hate to work with condensed formula, so if if you didn't mind it them Good. So first of all, how many functions did you guys find? And the answer was three. Okay, because I had this double bond. I had this oxygen over here, and then finally, I had that I a time. Okay, Now some of you guys might be wondering. What about Al Kane? We learned that Al Keynes single bonds between carbons and carbons are functional groups who talks about it. Actually, it turns out that Al Kane I should have mentioned earlier, is the only one that we don't consider a functional group. Because Al canes are the backbones for all of organic chemistry. So and they happen to not be very functional. In fact, they barely do anything. So when we're talking about functional groups, we're talking about things that are different from Al Cane. So that would be these three things. So what was the name of this first one? This would be an AL Keen. Okay. What was the name of this one right there? This one actually gets tricky because I want you to name degrees too. So this would be an alcohol. Hey, lied. And particularly it would be a secondary Aqil Hill. A Why is that? Because it's attached to two carbon groups. The carbon here. Remember that iodine? It would be named as a hydrogen. So I would count one carbon two carbons, cool. And then finally What did you guys get for this last one? This would be either okay, because this falls into the r. O r category where I have r O. R. And there's no carbon deals around. So this would not be like an Esther or anything like that. Cool. So does that make sense to us so far? Hopefully, this is helping you guys to reinforce all the groups that we just learned. So let's go ahead and go to the next page.
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Other Carbonyl Compounds
14
concept

Recognizing acyl chlorides and anhydrides.

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So now we're gonna work on some groups that not all books make you know, But your book does. So we're gonna go ahead and go over them just to be safe. Alright, So ASIO chloride eso chloride. You can think of it like an alga high. But instead of having an h, it has a c l. Okay. And the actual chloride has a condensed structure of basically are C o c l. Okay, so if you ever see that, that's an ASIO chloride. We're not gonna work with these a lot in Oracle one. Okay? We're actually not going to see these again until or go to We're gonna work with them a lot, Okay? But it's cool. It's good that you guys know these ahead of time. Then you've got another one that has to do with carbon eels, and that's anhydride. Okay, sending hydrate is a little bit tricky. Think of it almost like an ether R o r. But instead of having just our groups, it has carbon deals on both sides. OK, so it turns out that the way to name it and hydride through condensed structure is pretty tricky. The way that I mean, sometimes it's just listed out exactly the way it looks. So that would be Let's just write that out. Ch three c 00 see O C h three. Okay, so you can see that was a little bit tricky. Alright, um but sometimes it's also written with the O in the middle leading off. And that's the one that I happened to see a little bit more. So that would just be that you take the oh, and then you have everything on both sides since they're the same in this case in parentheses. So then that would just be C o. And then our whatever our group you have. But that would be this Our group right here in this, Our group. Right here, Times two. And that basically tells you that you have. We're splitting this thing down the middle, and you've got one of these things and you've got the second one there. And both of them are C o R. All right, so there you go. Eso chloride and hydride. You're not gonna tow work with these too much, but maybe just recognize them for the test
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15
concept

Recognizing sulfur compounds

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then finally, we've got sulfur compounds. Now, why am I listing oxygen again? Because sulfur happens to be right below oxygen on the periodic table. So it's gonna make very similar structures to oxygen. Okay, So what I want you to think of is, what would the structure be like? If it was an oxygen, what would it be called? And then what is it called if it's a sulfur? So let's start off with the oxygen one. Because I know you guys can help me with these. What type of group do we make if it's terminal? Basically, if the always at the end of a carbon chain, what is it called? Good job. That's called an alcohol. You got this. All right. How does its internal meaning that the O is sandwiched between two carbons hit? We just talked about this e sir. R o r scary stuff. Right, So there we go. We have our terminal alcohol terminal. Oh, is that alcohol internal? Oh, isn't either. Ok, so now let's talk about the sulfur sulfur. Like I said right underneath. Oh, so it's still wanna have to bonds. It's gonna make very similar compounds. If the s is terminal. It's gonna instead be called instead of alcohol, it's gonna be called a file. Okay, So, Thile instead of alcohol, and then instead of an ether, if it's on the inside, meaning it has carbons on both sides, it's gonna be called a sulfide. Okay, so these air just memory names that you literally need to memorize. You don't necessarily need to know degrees for these, but if you were asked the degree of a file, it would be the same way as an alcohol. So this would be what we would actually call a primary file because it has only one carbon attached to that carbon.

Since sulfur is directly under oxygen in the periodic table, it makes analogous structures. These have different names depending on whether the sulfur is terminal (like alcohol) or internal (like ether). 

Content
  • Thiol Condensed Structure = -RSH
  • Sulfide Condensed Structure = RSR

 

Alright, now who's ready for some Practice Questions? Let's see if you can name all of the functional groups in the following 3 questions. 

 

If you get stuck, just pause the video and scroll up! 

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Problem

PRACTICE:The following molecule contains several functional groups. Of the choices given, select the most appropriate answer (not all functional groups may be listed). 

17
Problem

PRACTICE:Identifying functional groups. Select the most appropriate answer. 

REMEMBER the A-TEAM gets degrees!

 

That is Alcohols, Alkyl Halides and Amines. 

Also, don't forget about Amides, they are part of the A-team as well.:)

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Problem

PRACTICE:Identifying functional groups. Select the most appropriate answer. 

Congratulations, you made it to the end! Now let's move on to the next topic. 

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