Chemically initiated electron exchange

The decomposition of dioxetanone may involve the chemically initiated electron-exchange luminescence (CIEEL) mechanism (McCapra, 1977 Koo et al., 1978). In the CIEEL mechanism, the singlet excited state amide anion is formed upon charge annihilation of the two radical species that are produced by the decomposition of dioxetanone. According to McCapra (1997), however, the mechanism has various shortfalls if it is applied to bioluminescence reactions. It should also be pointed out that the amide anion of coelenteramide can take various resonance structures involving the N-C-N-C-O linkage, even if it is not specifically mentioned. 

Schuster, G. B. (1979). Chemiluminescence of organic peroxides. Conversion of ground-state reactants to excited-state products by chemically initiated electron-exchange luminescence mechanism. Acc. Chem. Res. 12 366-373. 

CIEEL Chemically initiated electron-exchange luminescence... 

It was suggested that the mechanism of this reaction can be explained on the basis of a "chemically initiated electron exchange luminescence (CIEEL)" (49,50) according to the following scheme ... 

B. Electron-transfer-induced Decomposition Chemically Initiated Electron-exchange Luminescence (CIEEL)... 

This second chemiexcitation mechanism was formulated by Schuster as the Chemically Initiated Electron Exchange Luminescence (CIEEL) mechanism and involves an initial electron-transfer (1 et) from the catalyst, known as activator (ACT), to the peroxide and chemiexcitation is achieved by a back-electron transfer (A bet) after peroxide... 

Chemically Initiated Electron Exchange Luminescence (CIEEL) acridinium salts, 1256 alkaline phosphatase, 1193-8 1,2-dioxetanes, 1182-200 firefly bioluminescence, 1191-3 intermolecular, 1213-15, 1231-6 intramolecular, 1214-15, 1236-8 luminol, 1247-8... 

Eberson introduced the concept of a dissociative ET to peroxides some time ago. There have been attempts to apply Marcus Theory to the ET reduction of diaroyl peroxides in connection with the mechanism of the chemically initiated electron exchange luminescence (CIEEL)." " The... 

The catalyzed decomposition of energy-rich organic peroxides is another typical reaction of this type. It was called "chemically initiated electron-exchange luminescence" (CIEEL) by Schuster, who used organic compounds as redox catalysts (14). However, transition... 

The mechanism of chemically initiated electron exchange luminescence (CIEEL) has been specified and studied in solvents of different viscosities [226-230]. The intramolecular electron transfer in the oxyaryl-substituted adamantyldioxetane anion D [2 (the boldfaced numbers refer to the numbered structures 1-5 in Fig. 3.77)], followed by decomposition of the latter into two radicals A and M (5), allows them to diffuse freely in and out of the cage until the backward electron transfer (BET) excites the methyl-m-oxybenzoate anion M (4), as shown in Figure 3.77. In general, the intermolecular BET mechanism of excitation (right branch) competes with a direct chemiexcitation in the course... 

Chemiluminescence. The mechanisms behind this phenomenon, as induced by the reaction of, e.g. diphenoyl peroxide and an easily oxidized fluorescent molecule has been brilliantly illuminated by Schuster and co-workers (Schuster, 1979b Koo and Schuster, 1978) who proposed the CIEEL pathway (Chemically Initiated Electron Exchange Luminescence) according to (12). Note that two electron-transfer steps are postulated, the... 

In recent years several new dioxetanes substituted with easily oxidized groups, notably various aminoaryl groups, have been prepared and studied. Also in recent years, the chemically initiated electron-exchange luminescence... 

The proposed mechanism for the activator-catalyzed chemiluminescence of dimethyldioxetanone is the general mechanism identified as chemically initiated electron-exchange luminescence (Schmidt and Schuster, 1978a Adam et al., 1978). The CIEEL sequence as applied to dimethyldioxetanone is shown in Fig. 8. In short, the light-generating sequence is initiated by electron transfer from the activator (act) to the dioxetanone. Subsequent decarboxylation gives acetone radical anion. Annihilation of acetone radical anion and activator radical cation generates the excited state of the activator. 

---