[lespaul]

Hi All,

Im working on a project and Im using flourescence as an indicator of a specific reaction.

QUESTION:

Can anyone provide some basic rules of thumb on the structure of a compound and its ability to fluoresce. By this I mean - do ALL compounds that fluoresce NEED to have a aromatic ring - or can a straight chain, aliphatic compound, lipids, carbohydrates, etc fluoresce as well?

I know there are probably exceptions with all compounds-  but just looking for some basic correlation between structure and ability to fluoresce.

Thanks
J

[Hybrid]

i know that it must be rigid aromatic , this may be helpful

http://chemwiki.ucdavis.edu/Physical_Chemistry/Spectroscopy/Electronic_Spectroscopy/Electronic_Spectroscopy%3A_Theory#Fluorescence_and_Structure

[jeffrey.struss]

It does not have to be cyclic but it helps, there are polymers like polyethylene that fluoresce. Quite simply it helps to remove vibrational modes of relaxation from the fluorophore. Vibrational modes are encountered in the IR and they are a non-radiative means of getting rid of excess energy.

Note: None of this applies to metal based fluorescence which is an entirely different issue.