Gualterio_Malatesta - 8-1-2010 at 09:50
Hey guys!
It`s been bothering me for a while already.
How those ultraviolet fluorescent, but normally invisible dyes are made?
Is their production feasible at an average kitchen lab?
And what interests me most of all, are those coloured UV dyes, like red and blue. Cause I saw colorless UV dyes being sold, but never colored.
Any info on that?
P.S. Fantastic forum, you are doing a great job!!!
Best regards!
bbartlog - 8-1-2010 at 10:16
Not sure which products specifically you are thinking of. Some coumarin derivatives are colorless but fluorescent, for example umbelliferone. The
synthesis of some of them looks not too forbidding if you have the precursors (e.g. ethyl acetoacetate), but if you had to start with purely OTC
compounds I think it would be quite a bit of work.
Picric-A - 8-1-2010 at 11:42
I too would be very interested in making some longwave UV flourescent dyes!!
The synthesis of umbelliferone seems fairly simple:
Gualterio_Malatesta - 8-1-2010 at 12:07
That`s a start.
I wonder what are the colored dyes constituents?
Picric-A - 8-1-2010 at 12:15
My guess is they mix things like Umbelliferone with a flourescent dye such as :
9,10-diphenylanthracene (DPA) emits blue light
1-chloro-9,10-diphenylanthracene (1-chloro(DPA)) and 2-chloro-9,10-diphenylanthracene (2-chloro(DPA)) emit blue-green light more efficiently than
nonsubstituted DPA; dihydro(DPA) is purple
9,10-bis(phenylethynyl)anthracene (BPEA) emits green light
1-chloro-9,10-bis(phenylethynyl)anthracene emits yellow-green light, used in 30-minute high-intensity Cyalume sticks
2-chloro-9,10-bis(phenylethynyl)anthracene emits green light, used in 12-hour low-intensity Cyalume sticks
1,8-dichloro-9,10-bis(phenylethynyl)anthracene emits yellow light, used in Cyalume sticks
Rubrene emits yellow
2,4-di-tert-butylphenyl 1,4,5,8-tetracarboxynaphthalene diamide emits deep red light, together with DPA is used to produce white or hot-pink light,
depending on their ratio
Rhodamine B emits red light. Is rarely used as it breaks down in contact with phenyl oxalate, shortening the shelf life of the mixture
5,12-bis(phenylethynyl)naphthacene emits orange light