Hey, everyone. Let's take a simple look at conjugation and our lambda max. Now remember, only organic molecules with conjugated pi bonds will absorb a UV Vis spectrum. And the trend is the greater your conjugation, then the greater your lambda max. Remember, conjugation is just alternating pi bonds and single bonds.

Now if we take a look here, we have 1,3-butadiene, and we would say that this is a conjugated system because it goes pi bond, single bond, pi bond. Here, we'd say its theoretical lambda max value is going to be 217 nanometers. Now, if we go over to 1,3,5-hexatriene, this is also conjugated and it has even more conjugation because here it was pi bond, single bond, pi bond. Here, it's pi bond, single bond, pi bond, but then also additional conjugation, single bond, pi bond. So there's even more conjugation, and we said the trend is the higher the conjugation, then the higher lambda max.

Here, its theorized lambda max value is 258 nanometers. So we can see that the number has gone up. And this is the trend we need to remember: UV-Vis spectroscopy looks at these conjugated systems. The greater the conjugation that we have, the higher the lambda max will be. Later on, we'll go into further detail looking at this more theoretically, as well as doing calculations where we could figure out an estimate of our lambda max.

For now, just remember this general trend: The higher the conjugation, the higher the lambda max value.