Bis(2,4,5-trichlorophenyl-6-carbopentoxyphenyl)oxalate
IUPAC name	Bis(2,4,5-trichlorophenyl-6- carbopentoxyphenyl)oxalate
Other names	CPPO
Identifiers
CAS number	[30431-54-0]
PubChem	93137
Properties
Molecular formula	C26H24Cl6O8
Molar mass	677.18 g∙mol-1
Melting point	188–192 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references

Bis(2,4,5-trichlorophenyl-6-carbopentoxyphenyl)oxalate (CPPO) is a solid ester whose oxidation products are responsible for the chemiluminescence in a glowstick. 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. 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 1960's, the formulation containing CPPO, a fluorescor, and a glass capsule containing hydrogen peroxide and a base catalyst, all in dialkyl phthalate solvents, was marketed as Cyalume.

The following colors can be produced by using different dyes:

References