Functionalized adamantylideneadamantane 1,2-dioxetanes: investigations on stable and inherently chemiluminescent compounds as a tool for clinical analysis

Photophysical and thermodynamic properties of adamantylideneadamantane 1,2-dioxetane (1) and some functionalized derivatives, useful as thermochemiluminescent labels, are summarized. The emission of light from these compounds is stimulated simply by thermal activation. The low fluorescence efficiency of S1-adamantanone, the emitting product, causes the chemiluminescence efficiency to be moderate (φCL = 10-4). The quantum efficiency of chemiluminescence φCL can be increased effectively through radiationless energy transfer to a fluorescent acceptor. The donor acceptor pair 1 and 9,10-diphenylanthracene (DPA) is investigated in terms of Förster's theory. Proteins, labeled with derivatives of both 1 and DPA show increased thermochemiluminescent specific activity, in accord with this theory. Upon complexation with cyclodextrins, the evaporation of 1 and its derivatives at 240°C is inhibited. These complexes show a perfect dose-response linearity over a large range of concentration. Complexation also increases the reproducibility of chemiluminescence detection. Association constants for 1 and a derivative with both β- and γ-cyclodextrin are presented