Hydrogen peroxide reaction with lucigenin

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). 

Classical chemiluminescence from lucigenin (20) is obtained from its reaction with hydrogen peroxide in water at a pH of about 10 Qc is reported to be about 0.5% based on lucigenin, but 1.6% based on the product A/-methylacridone which is formed in low yield (46). Lucigenin dioxetane (17) has been prepared by singlet oxygen addition to an electron-rich olefin (16) at low temperature (47). Thermal decomposition of (17) gives of 1.6% (47). 

The lucigenin radical 78 is not involved, according to Janzen and coworkers 136), in the direct formation of this cyclic peroxide one would, however, expect a reaction of 78 with oxygen radical anion to be a possible way of forming the cyclic peroxide, although lucigenin radicals were not detected in the presence of hydrogen peroxide. 

HTAC and HTAH have been used as surfactants in the chemiluminescence reaction of lucigenin (10,10 -dimethyl-9,9 -biacridinium dinitrate) with biological reductants (such as fructose, glucose, ascorbic and uric acid) or hydrogen peroxide [38],... 

The mechanism of 1,2-dioxetane formation in the reaction of lucigenin with hydrogen peroxide suggests a nucleophilic attack of peroxide anion on position 9 of the acri-dinium ring, followed by deprotonation and subsequent formation of 1,2-dioxetane ring... 

Similar to luminol and lucigenin, both lophine and gallic acid also react with alkaline hydrogen peroxide to yield chemiluminescence. In all of these reactions, the emission intensity is proportional to transition metal ion catalyst concentration over finite ranges. Table 1 provides an abbreviated comparison of the selectivity and sensitivity available with these systems. 

Other chemiluminescence FIA methodologies for AA determination are based on AA acidic reduction of potassium dichromate to generate Cr(III) and subsequent luminol-hydrogen peroxide-Cr(III) chemiluminescence reaction [87,88], and on chemiluminescence reaction of AA with potassium permanganate in the presence of formaldehyde [89,90], formic acid [91], or CdTe nanocrystals [92] as sensitivity enhancers. Quinine is also used as an enhancer of chemiluminescence produced by reaction between AA and Ce(IV) in acid media [93]. Perez-Ruiz et al. [94] proposed a chemiluminescent reaction, in alkaline solution, of lucigenin with the products from the photooxidation of AA sensitized by toluidine blue. 

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