Frank McCapra

Stable and versatile active acridinium esters II

The synthesis of acridinium esters with a linking group directly attached to the acridine nucleus is described. This strategy will allow the widest possible choice of variously substituted phenyl esters without restricting them to those structures bearing linking groups on the phenol.

Biosynthesis of luciferin in Pyrophorus pellucens

The luminescent click beetle, P. Pellucens, incorporates DL-crystine into the substrate in the light reaction, showing that luciferin is synthesised in adult beetles.

Alternative mechanism for dioxetan decomposition

It is suggested that dioxetans substituted by, or reacting with, compounds with strongly electron-donating groups decompose via radical ions and that excitation occurs by electron transfer.

The fluorescence of the chromophore of the green fluorescent protein of Aequorea and Renilla

A possible explanation for the lack of fluorescence in the isolated chromophore of the green fluorescent protein found in bioluminescent coelenterates has been provided by the synthesis of model compounds and a more satisfactory structure is suggested.

Singlet excited states from dioxetan decomposition

Isolable dioxetans usually afford triplet rather than singlet excited products but we now show that high yields of excited singlet states are obtainable from stable dioxetans by appropriate substitution; a remarkable rate acceleration of the chemiluminescent reaction by surfaces is observed.

Possible mechanism for bacterial bioluminescence and luminol chemiluminescence

The structures of the peroxides which react with flavinium salts with light emission, supported by a study of isotope effects, suggest an electron transfer mechanism with concomitant loss of a proton or H-atom; the mechanism may be applicable to the in vivo bacterial system and to luminol.

Reaction of singlet oxygen with hindered olefins: evidence for a perepoxide intermediate

Isolation, along with expected product, of 1,2-dioxolans of rearranged skeleton from the reaction of singlet oxygen with certain hindered alkenes suggest the intermediacy of a dipolar species such as a perepoxide.

Chemiluminescent Schiff bases

Although very few examples of chemiluminescent Schiff bases have been described, and attempts to extend this class of reaction have hitherto been unsuccessful, it is now shown that these compounds are generally chemiluminescent on oxidation, with reasonable efficiency.

Model reactions for bacterial bioluminescence

Acid-catalysed addition of hydrogen peroxide to n-butyl vinyl ether gave a separable mixture of the hydroperoxides (1)–(4); peroxides (1)–(3) undergo chemiluminescent reactions in acetonitrile with 1,3,10-trimethylisoalloxazinium perchlorate in the presence of triethylamine, and the flavin analogue catalyses the decomposition of the peroxides.

Mechanism of Schiff base chemiluminescence: evidence for an intermediate dioxetan

The decomposition of a derivative of a peroxide obtained by oxidation of a Schiff base shows that chemiluminescence occurs via an intermediate dioxetan.