So remember that it's usually easier to name ethers in the common name system, meaning that it's just both the R groups and then ether at the end. Well, the same is going to apply to sulfides. Sulfides are typically easier to name in the common name system, so let's start with that one. I'm just going to write here 'common' and let's figure it out. What are the 2 R groups? Well, in this case, I've got an ethyl on one side and a benzene ring by itself. It's not called benzene. It's called phenyl. Remember that? So I just have to put them in alphabetical order. The common name is going to be easy. This is just ethylphenylsulfide. Cool? So that one wasn't so bad. You can see how if it would have been an O there, it just would have been ether. Same thing.

Now let's go with the IUPAC name. The IUPAC name is a little bit more complicated because remember that the IUPAC name, you have to name the bulkiest or the longest root and then you have to name the SR or the OR, whichever one it is, as the substituent. So in this case, I have two different possibilities. I have either the two-carbon chain here that's ethyl or I have the six-carbon ring on the other side, which is phenyl as a substituent, which one is going to want to be the root? I'm going to go with my benzene ring because my benzene ring is overall bigger than the two-carbon chain on the other side. So, what that means is that instead of calling this a phenyl group, I'm just going to call it benzene because that's going to be the root. So now if this is benzene, I'm just going to scratch out phenyl, it becomes benzene now because that's my root. Then, what is the substituent? Well, my substituent is usually called, we said it's called an alkylthiol group. So in this case, the alkyl is just ethyl. So the name, the IUPAC name here would be ethylthiobenzene. All one word. Okay? You might be wondering, well, John, do we have to say the location of it? Do we have to say that it's like 1-ethylthiobenzene? No, because there's only one substituent, so it's always assumed that you can start at the 1. But if you wanted to, you could say as well that it is 1-ethylthiobenzene. Okay? But typically, if you see it on your exam or in the book, you'll see that the number 1 is omitted if there's only one substituent present. We usually only use locations on rings if there's more than one substituent, for example, 2 or 3. Okay? Awesome guys. So hopefully that made sense. Let's keep moving on.