Cocaine and UV absorption

[joho]

What parts of the cocaine molecule are responsible for UV absorbance?

 

Now I understand that this is the shared and lone pair electrons and the aromatic rings, but not sure why and where the electrons are.:eek_big:

[Igby]

Well, radiation in the UV and visible regions of the spectrum has the energy to excite electrons in one bonding orbital into an orbital with a higher energy. The electrons which are more easily bunted into a higher orbital are electrons which are involved in "conjugated pi-bonds". Basically, a conjugated molecule has alternating single and double/triple bonds in at least part of the molecule. Aromatic rings, of course, are conjugated.

 

Any further explanation than that is beyond me. Heh. :hihi:

[joho]

Thanks Igby.