Dear Sir,

Your sentence  shows hat you are not familiar with internet searching.

I am not able to locate any reference where aminocoumarins have been studied at low temperatures in non-polar solvents?

Please consult Google Scholar and not Google and give your question in the mask .  . On other part, your posted question is too vague (quite bad formulated) . Why??

- What a kind of aminocoumarins? Define  the other substituents!. Do you mean free amino group like Coumarin 151 or monoalkylamino  like Coumarin 500 or dialkylamino like Coumarin 30?

If you want to study the photophysics of aminocoumarin like a scientist and not like a student, please define  low temperature (e.g. liquid nitrogen)  and define non polar solvents . Please note that you must have a solution that freezes transparent like a glass.

The concentration of your amino coumarin must be low to avoid crystallization when the solution is going in the frozen state.

Please order the Kodak optical products booklet (It is free of charge) for a lot of infos.

JRG