We have already touched on the air in several videos. They are useful aprotic solvents in some reactions It happened. But I thought there were already a couple of videos on the air It's time to dedicate. And like a lot of what we do in organic chemistry a good way to introduce ourselves to molecules and by their appearance, is to name them. Let's look at one or two. And you've already seen a few. Let's say we have this molecule. I have two ways of naming them I will show. The common name is perhaps for ethers is the most important thing. Because, as you can imagine, this is a more general name. People say that. Then call it IUPAC I'll show you what to call it. Let me spell it. IUPAC name, opening International Pure and Applied Chemistry It is unity.
And they are for all organic molecules prepare official naming protocols. This is actually the case with alkanes and alkenes is the traditional method we use. But when it comes to broadcasts, the common name is more widespread. The common name of this molecule. Here you look at two carbon groups. Let's see. Let's look at this. This is the ethyl group. This is the ethyl group here. You have one or two carbons. Then you look at the other carbon here. This is also an ethyl group. One, two cabs. So, this is a sheep spell, that's it ethyl group. The common name for this is simply diethyl ether. The ether tells you that this part says that there are two ethyl groups you have oxygen between. This is a common name. Now the International Organization of Pure and Applied Chemistry Let's look at the naming. Similar to what you do to name other items do things.
You look at the longest chain. Let me shoot again. Maybe I write common names on the left. IUPAC names on the right. Let's redraw the common name of the sheep, diethyl ether. You look at the longest chain. In this case, here are the two longest chains. It has one or two carbons. Then you have this, you have one or two carbon. You can choose both. I will just choose it. It has two carbons and no double bonds. He is ethane. You say I have an alcohol group. We end -oxy because oxygen var. But the -alk part has two carbons, one, two. We call this ethoxy. Another way to call it the first carbon is to look at the combined ethoxy group. We begin to call this side of ethane, because he's from here to the first carbon united.
We call this 1-ethoxyethane. You will almost never see it called that, although the official name. You will see more diethyl ether. Well, at least I didn't go down without explaining myself first. You only find two groups. In the end, you broadcast. You know, there's oxygen in between. Let's look at more. Suppose there is such a molecule. I have this molecule. In general, the groups on both sides of the oxygen you look. Here-let the sheep in a different color- our in the group on the left we have one, two, three carbon. It's a propyl group, though merged with the carbon in the middle. This is also an isopropyl group. Ours on the right we just have one carbon. This, again, I write in the sky, this is also a methyl group.
The general way to call it, you both You record the group and then add the ether. And you write them in alphabetical order. Comes before I m. So the common name is isopropyl methyl ether. Now let's look at the name IUPAC, find the longest carbon chain. Let me re-draw the molecule itself. Let me draw the same thing here. What is the longest carbon chain? We have one, two, three carbon. We only have one carbon here. This is the longest carbon chain. It has three carbons and no double bonds.
-Meat, -met, -prop, -propyl, or propane. This is the longest carbon chain. So we write propane here, because we use the IUPAC naming mechanism. Then we look at the methoxy group here. And I call it the methoxy group because it exists. It gives us oxy. And here is my methyl group. This is a methoxy. You remember that this -met is a carbon means. We add oxygen because that's where the oxygen is. And it combines two carbons in a propane chain, whichever side you number, or from your digitization. One two Three. This is 2-methoxypropane. Let's look at another. Let's do one. I think you can at least name the ethers simple you will get the main idea for. Let's put a chain here. Then it is combined with an oxygen. We have another carbon chain. We have another chain here. Copy and paste the sheep not to smoke again. I copy and paste. Good. Let's first make a general naming. Always more is interesting. Here one, two, three, four, five, six We have carbon. Our cyclohexyl group on the left located. On the right there is one, two, three carbon.
This is also a propyl group. When it comes to ether, it's just a group align in alphabetical order and end with an ether do you add. This is cyclohexyl. C comes before p. This is cyclohexyl propyl. Shade with sheep yellow. Cyclohexyl propyl ether. Now let's look at the name IUPAC. You are looking for the longest carbon chain. In this case, it will be cyclohexane. One, two, three, four, five, six carbon. There are only one, two, three. It also plays the role of the spine. We write cyclohexane. There is no double connection, it is hexane. This is cyclohexane. If you had these three carbons, it would be propyl. But it's not just three carbons.
It has three carbons and oxygen. We call it propoxy. This is a propoxy group. And you don't have to number it, because it's just can combine with one of these carbons. It will be the same molecule. You can simply call it propoxy cyclohexane. Let me do this a little closer to cyclohexane. Cyclohexane propoxy. But again, this is more of a common name we will see a lot. Now we have named a few, Let's look at a few features.
We've already seen a few of them times, especially in our Sn2 reactions- we don't want it to be a proton There are places. We actually used diethyl ether. In general, ethers are good solvents. They are not reactive. That is, they are good solvents. Especially aprotic solvents. I remembered the aprotic electron your hydrogen will lose an electronegative atom like oxygen it doesn't happen. And the proton just flies around, they can go and react with other things. In no case is it directly attached to oxygen no hydrogen. That is, it is an aprotic solvent.
And in the absence of hydrogen binding to oxygen You also don't have hydrogen bonds. Again, in the water There is a situation where a sheep pulls several water molecules into the water a situation arises that oxygen wants electrons. It has a half negative load. Hydrogen loses electrons, or with them spends less time. It has a half positive charge. It has a half negative charge of oxygen.
Together with hydrogen, which has a semi-positive charge combine with semi-negatively charged oxygen. You have such a hydrogen bond. This hydrogen bond creates water. It pulls the molecules together. Your more to melt or boil it you have to expend energy. Separation of molecules for. This also applies to alcohol. Alcohols simply have a hydrogen with oxygen, but they still have hydrogen bonds available. As for ethers, they have no hydrogen bond. I have one R and one R on each carbon chain I will show as.
I'll write an R bar, here's his I am writing to show the possibility of a different carbon chain. R is radical. We should not confuse it with free radicals. They are completely different things. This R simply combines with this oxygen is a carbon chain. But here's half the positively charged hydrogen transfer electrons to semi-negatively charged oxygen There is no such event. That is, you have no hydrogen bonds. Therefore lower melting and boiling of ethers there are points. It's easier to do that. You heat less to separate the molecules because they are firmly attached to each other not closed..