Bis(2,4,5-trichloro-6-(pentyloxycarbonyl)phenyl)oxalate
Bisoxalate is an organic compound with the formula. A white solid, it is classified as a diester of oxalic acid. It is an active ingredient for the chemiluminescence in glow sticks. It can be synthesized by reacting 2-carbopentoxy-3,5,6-trichlorophenol with oxalyl chloride.
When mixed with hydrogen peroxide in an organic solvent in the presence of a fluorescent dye CPPO causes the emission of light, following its degradation to 1,2-dioxetanedione :
The reaction rate is pH dependent, and slightly alkaline conditions achieved by adding a weak base, e.g. sodium salicylate, will produce brighter light. Developed by American Cyanamid in the 1960s, the formulation containing CPPO, a fluorescer, and a glass capsule containing hydrogen peroxide and a base catalyst, all in dialkyl phthalate solvents, was marketed as Cyalume. Current Cyalume products no longer use any phthalate solvents.
The following colors can be produced by using different dyes: