Lophine

A number of chemiluminescent reactions may proceed through unstable dioxetane intermediates (12,43). For example, the classical chemiluminescent reactions of lophine [484-47-9] (18), lucigenin [2315-97-7] (20), and transannular peroxide decomposition. Classical chemiluminescence from lophine (18), where R = CgH, is derived from its reaction with oxygen in aqueous alkaline dimethyl sulfoxide or by reaction with hydrogen peroxide and a cooxidant such as sodium hypochlorite or potassium ferricyanide (44). The hydroperoxide (19) has been isolated and independentiy emits light in basic ethanol (45). 

Figure 1 Chemical structure of (A) lophine (2,4,5-triphenylimidazol) and (B) pyro gallol.

Although bioluminescence had been observed in nature for centuries, that synthetic organic compounds could produce light was first established by Radziszew-ski [1, 2] in 1877 using lophine (2,4,5-triphenylimidazole) (Fig. 1). 

Lophine emits yellow CL upon oxidation by molecular oxygen in alkaline solution. The oxidation is believed to produce a free radical [3], which is further oxidized to a hydroperoxide, which is the light-emitting species [4-6], A number of chemiluminescent derivatives of lophine have been synthesized and have been shown to exhibit varying efficiencies of CL. Lophine has been used in the analysis of metal ions such as Co2+ that catalyze the chemiluminescent reaction between it and hydrogen peroxide [7], It has also been used as a chemiluminescent indicator in titrimetry [8],... 

Triphenylimidazole. See Lophine Triphendioxazine dyes, 9 259-261 Triphenodioxazine chromophores, 9 320... 

Lophine, chemiluminescence, 1212 LOQ (Limits of quantitation), 625 Low-density lipoprotein (LDL) o,o -dityrosine residues, 610 hydroperoxide determination, 675 oxidation, 610-11, 612, 613, 671 oxidized antibody determination, 633 TEARS assay, 667... 

The base-catalyzed chemiluminescence of triphenylimidazole (42, lophine) in the presence of oxygen, first reported by Radziszewski, was later shown... 

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