Bis ,4,5-trichloro-6-(pentyloxycarbonyl)phenylxalate (also known as bis(2,4,5-trichloro-6-carbopentoxyphenyl) oxalate or CPPO) is a solid

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

whose

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

products are responsible for the chemiluminescence in a

glowstick A glow stick, also known as a light stick, chem light, light wand, light rod, and rave light, is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light ...

. It can be synthesized by reacting 2-carbopentoxy-3,5,6-trichlorophenol with

oxalyl chloride Oxalyl chloride is an organic chemical compound with the formula (COCl)2. This colorless, sharp-smelling liquid, the diacyl chloride of oxalic acid, is a useful reagent in organic synthesis. Preparation Oxalyl chloride was first prepared in 1892 ...

. When mixed with hydrogen peroxide in an organic solvent (diethyl phthalate, ethyl acetate, etc...) in the presence of a fluorescent dye CPPO causes the emission of light, as per the following scheme involving 1,2-dioxetanedione (note that many side-groups of the aromatic rings are not shown.): : The reaction rate is pH dependent, and slightly alkaline conditions achieved by adding a weak base, e.g.

sodium salicylate Sodium salicylate is a sodium salt of salicylic acid. It can be prepared from sodium phenolate and carbon dioxide under higher temperature and pressure. Historically, it has been synthesized by refluxing methyl salicylate (wintergreen oil) with a ...

, will produce brighter light. Developed by

American Cyanamid American Cyanamid Company was a leading American conglomerate which became one of the nation's top 100 manufacturing companies during the 1970s and 1980s, according to the Fortune 500 listings at the time. It started in fertilizer, but added ...

in the 1960s, the formulation containing CPPO, a fluorescer, and a glass capsule containing

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

and a base catalyst, all in dialkyl

phthalate Phthalates (, ), or phthalate esters, are esters of phthalic acid. They are mainly used as plasticizers, i.e., substances added to plastics to increase their flexibility, transparency, durability, and longevity. They are used primarily to soften ...

solvents, was marketed as Cyalume. The following colors can be produced by using different dyes:

References

{{reflist Oxalate esters Phenol esters Chemiluminescence