Diphenyl oxalate

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Diphenyl oxalate
Skeletal formula
Ball-and-stick model
CAS number 3155-16-6 YesY
PubChem 18475
ChemSpider 17449 N
Jmol-3D images Image 1
Molecular formula C14H10O4
Molar mass 242.227 g/mol
Appearance solid
Melting point 136 °C (277 °F; 409 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Diphenyl oxalate (trademark name Cyalume) is a solid ester whose oxidation products are responsible for the chemiluminescence in a glowstick. It can be synthesized by fully esterifying phenol with oxalic acid. The reaction with hydrogen peroxide that diphenyl oxalate undergoes produces phenol and 1,2-dioxetanedione, which excites the dye and releases a photon as it decomposes to carbon dioxide.


The reaction rate is pH dependent, and slightly alkaline conditions achieved by adding a weak base, e.g., sodium salicylate, will produce brighter light. The 2,4,6-trichlorophenol ester of oxalic acid is a solid and thus easier to handle. Furthermore, since trichlorophenolate is the better leaving group, the reaction will proceed faster, again producing brighter light, as compared to the phenol ester.

The following colors can be produced by using different dyes:

Color Compound
Blue 9,10-Diphenylanthracene
Green 9,10-Bis(phenylethynyl)anthracene
Yellow-green Tetracene
Yellow 1-Chloro-9,10-bis(phenylethynyl)anthracene
Orange 5,12-Bis(phenylethynyl)naphthacene, Rubrene, Rhodamine 6G
Red Rhodamine B