in this video we're going to take a look at some stereo isomers and specifically we're going to focus on confirmational isomers so before we get into what confirmational isomers are we need to Define what stereo isomers are and they are structures that have the same structural formula so the same connectivity between atoms but the atoms are arranged differently in space and so there's a variety of different types of stereo isomers uh configurational isomers which have a couple of types and then as I said we're focusing on confirmational isomers here in this video so let's just get right into it so confirmational isomers are forms of the same molecule that have different confirmations so that's where the name is coming from because of rotation around a sigma Bond or if you remember a sigma bond is a single Bond so one thing to keep in mind here is that around a single Bond we can have free rotation so around each of these bonds here uh you can kind of picture that there's free rotation of those molecules and so specifically if you get rotation around these carbon atoms here you can end up with different forms or different confirmations of a substance so this one in particular here it's a one two dichloroethane um many different sort of forms of this is going to exist simultaneously in a sample of this particular substance or any of these substances that have these confirmational isomers uh these forms are interconverting constantly with each other and you can't really isolate any one particular form because no bonds need to be broken so these isomers just exist in a variety of different sort of ways you can see in this particular one if we look at the chlorine atoms for example in one confirmation the chlorine is pointing up in one and pointing down in the other and in the other one the chlorines are both pointing up we can draw an image looking along the carbon carbon Bond and these look a little weird because because they take the form of a picture like this where the three lines represent atoms that are attached to the first carbon and then at the back sticking out are the other atoms attached to the other carbon so in this first one a you can see if we have a chlorine pointing up and pointing down we could draw it like this and then the rest of these would be hydrogens it's called a projection you don't really need to know the name but just uh kind of gives you a visual of what that looks like along this carbon carbon Bond now this is really energetically favorable because those chlorines are big they want to be as far away from each other and so this is quite an energetically favorable confirmation the other one where the chlorines are both at the top here looks a little bit different just draw this in quickly and there we go so this is the one where it's got two chlorines up at the top there and this is what its Newman projection would look like now these two chlorines are really close to each other in space and so this particular confirmation is not as energetically favorable so it's likely this molecule spending more time in the first confirmation than the second but like I said all of these different conf formations exist and we can't isolate them because we can't stop a single bond from rotating around itself one other example of confirmational isomers which is kind of neat is the cyclical six carbon alkane so it's called cyclo which just means we have a ring structure and then hexane so a six carbon uh chain and the reason I say this one's kind of neat is because it does have a couple of confirmations that take some really neat shapes and if you have the opportunity to take a molecular model kit and build these to well you build cyclohexane and then try and manipulate it into these two confirmations without breaking any bonds the first confirmation is called boat confir confirmation and it kind of looks like a boat right and then the second confirmation chair looks like a chair and uh so like I said if you get a chance to play with some model kits and build these structures it's really fun once you kind of figure out the trick to interconverting between the chair and the boat confirmation without breaking any bonds so that's confirmational isomer that's it for this video we'll see you in the next one