Spectroscopic study of the authentic emitter of AMPPD chemiluminescence in alkaline aqueous solutionElectronic supplementary information (ESI) available: Additional data from single-photon counting experiments. See DOI: 10.1039/b922244h.

To design more effective CIEEL (chemically initiated electron exchange luminescence) systems demands a complete picture of the dynamics of the chemiluminescence, which is often a challenge. In this work, photoluminescence of the methyl m-oxybenzoate anion – the authentic emitter of AMPPD (3-[2-spiroadamantane]-4-methoxy-4-[3-phosphoryloxy]-phenyl-1,2-dioxetane) in aqueous solvent has been studied. Combining the effect of solvent properties, e.g.pH value, and spectroscopic studies employing steady-state and ultrafast time-resolved emission and absorption and 1H NMR techniques, a novel mechanism is proposed. We conclude that the deviation of emission peaks between chemiluminescence and photoluminescence of the authentic emitter of AMPPD i.e.the methyl m-oxybenzoate anion, in alkaline aqueous solvents is due to its hydrolysis, rather than the hydrogen-bonding effect as has been assumed so far. Besides, the hydrogen-bonding is suggested to play a key role in significantly decreasing the chemiluminescence yield of AMPPD in aqueous solution by shortening the lifetime of the excited authentic emitter to 10 ps order of magnitude – three orders of magnitude shorter than the previously reported value (∼10 ns). These results shed light on the chemiluminescence dynamics of AMPPD and facilitate the design of more effective CIEEL systems. [ABSTRACT FROM AUTHOR]