00:01
So you've been learning about benzene, and i think you've been learning about the, or by now you should understand how important resonance is and how important conjugation is to lowering the energy of certain species.
00:15
Right.
00:16
So it's kind of unusual that this biphenal ring here isn't flat.
00:24
And by flat, i mean both of those rings are in the same plane.
00:27
And the question asks us to figure out why.
00:32
So if it were just regular bifenal, it might be safe to assume that they would form a conjugated system.
00:40
But in this dimethyl substituted bifanil, you have those two benzene rings at a 63 degree angle.
00:46
So when they say that, they're talking about this angle here is 63 degrees.
00:56
So i tried to draw a 3d version of that.
00:59
And i'm not sure if i did a very good job.
01:02
But if you look at the flat version, right? so this is why it is optimized.
01:08
The lowest energy confirmation is having those phenal groups at a 63 degree angle...