[Silica]

When I make a compound, it is often a surprise to me that it shows up on the TLC plate as a bright spot under UV light. 

For instance, I was modifying another part of the molecule, starting with an ortho-alkoxybenzoic acid.  Ether cleavage occurred as an unexpected side reaction, giving an ortho-hydroxybenzoic acid (a salicylic acid).  This was confirmed by NMR spectroscopy after isolating the salicylic acid byproduct. 

The evidence I had that this byproduct was showing up was an extra spot on the TLC plate.  The spot for the salicylic acid derivative gave off a blue fluorescence under a short wave UV lamp, whereas the spots for the ortho-alkoxybenzoic acid starting material and main product did not fluoresce.  The phenol fluoresced, and the phenyl ether did not.     

Often, one or more components in a reaction mixture will fluoresce like that, whereas the rest don't.  I think it would be a great way to begin identifying reaction products and tracking down side reactions if there were a review or a textbook that catalogued the types of molecules or functional groups that make a molecule fluorescent.

Is anyone here familiar with such a list of compound types that fluoresce?

Thanks

[Ψ×Ψ]

If you're dealing with more than one aromatic ring in a molecule, you frequently see glowy spots.   
But not always.