Hey, guys, and let's talk about a new concept called conjugation. So conjugation exists when three or more atoms with the ability to resonate are next to each other or back to back. Another way that you can think of it is that they're orbital's are overlapping. Now. This idea of resonating or resonance is an old concepts from organic chemistry, one that you guys should all be relatively familiar with. We've all drawn a resident structure at this point. So might be wondering what Johnny, what's the difference between resonance and conjugation? And essentially, there isn't really a difference there. Two names for the same idea, whereas to resonate resonate is a verb, right. If you resonate something that's an action right, will conjugation or conjugated conjugated would be the adjective that describes that you could do that. Okay, so I don't want to get too much into grammar, but basically just saying that something that is conjugated has the ability to resonate. OK, so they're really the same. Similar words for the same idea. So now what does this mean? Well, conjugation provides a highway or an electron highway for electrons to d localize from one side of a molecule to another. And we all know that de localization provides stability for molecules. That's something that we learned a long time ago about resonance. Okay, so it turns out that these conjugated molecules, because there have the extra stability, they're gonna display unique chemical reactivity that we're going to spend a few topics talking about. Okay, Now, in another note, that's pretty much unrelated to everything I just said. There's a new important side note for you to know, Which is that the higher the level of conjugation in a molecule, the higher the UV wavelength is gonna be in a UV viz spectrometer. Okay, now, why am I mentioning this? So the higher the UV wavelengths with if you guys remember wavelength looks like that, Okay, Now, the reason I'm mentioning that is because I'm really not going to spend any time talking about you. Viv is spec. But this is the Onley meaningful application that you really need to know about it for organic chemistry one and two, which is that as your conjugated compounds have more and more congregation, meaning that more and more atoms can resonate together, the higher the wavelengths tend to be for this UV spectrometer, and this could be a multiple choice question. Or it could be a free response question that you get asked. So that's just something that I wanted to throw in there. Okay, so now it's actually talk about the properties of the types of molecules that are conjugated. Well, we just said that three atoms with the ability to resonate have to be back to back. So what type of atoms are the ones that can resonate? Well, we all know that pie bonds can resonate. So we're gonna put here one pie bonds. Okay, now, a pie bond doesn't just have to be a double bond. It could also be a triple bond because we know that triple bonds actually have two pi bonds in them. So double bonds and triple bonds are definitely kid bull resonating. Now, the other ones that are capable of resonating would be ones that have orbital's that air free to accept or donate electrons. So that would be, for example, if you have a basically a lone pair or an anti on. Okay, so I'm gonna put here an eye on or lone pair. Really, depending on what the formal charges of that molecule in terms of resonating the idea of having a lone pair or negatively charged an ion, really? They resonate the same exact way. Okay, the whole deal of having a negative charge just has to do with what's the formal charge of that specific Adam. So for the context of conjugation, we're gonna treat these exactly the same. Okay, so that's what happens if you have two electrons in your orbital. But we know that you don't have to always put to another idea is Well, what if I just put one electron in the orbital? What's that called? That's called a radical Radicals are also capable of resonance or conjugation. Okay. So radicals can also congregate on. The last idea would be Well, how if we put zero electrons in there, then that would be a positively charged um, Adam. So that would be a cat ion. Okay, so these air all of the types of Adams that I want you to think about when we talk about atoms that can resonate. We're just saying that here actually have five atoms listed, right? Because I have the three different charges. I have an eye on the radical to Cat ion. And then I also have the two atoms from the pi bond. So all I'm saying is that you need some combination of these three atoms in a row that would provide for for conjugation to take place. Okay, so what we're gonna do is we're gonna do this practice problem, and you have to identify which of the following molecules exist in a conjugated state. So go ahead and use what I talked about earlier, above as a reference and figure out which of these molecules are conjugated and which ones are not conjugated. So go ahead and do that now.
