TY - JOUR
T1 - Mechanistic investigations of the 2-coumaranone chemiluminescence
AU - Schramm, Stefan
AU - Navizet, Isabelle
AU - Prasad Karothu, Durga
AU - Oesau, Pascal
AU - Bensmann, Veronika
AU - Weiss, Dieter
AU - Beckert, Rainer
AU - Naumov, Panče
N1 - Funding Information:
This work was partially financially supported by the New York University Abu Dhabi. This research was in part performed by using the Core Technology Platform resources at the New York University Abu Dhabi. We thank the service team of the IOMC and IAAC of the Friedrich-Schiller University Jena for their help with the NMR and EPR experiments, as well as the computational facility of the Friedrich-Schiller University Jena for providing the computational resources. We thank Dr P. Commins for proofreading of the manuscript. S. S. acknowledges the Friedrich-Ebert Stiftung for financial support.
Publisher Copyright:
© 2017 the Owner Societies.
PY - 2017
Y1 - 2017
N2 - 2-Coumaranones are evolving as a new, efficient, versatile, and synthetically accessible platform for the next generation chemiluminescent probes. Despite the favorable quantum yields, the exact mechanism of their chemiluminescence remains elusive. Here, we analyze the details of the mechanism of the 2-coumaranone chemiluminescence using a combination of experimental and computational methods. By using EPR spectroscopy we show that superoxide radical anions are involved in the reactions, in support of the hypothesis that the mechanism includes a single electron transfer step. The decomposition of the high-energy intermediate, 1,2-dioxetanone, is described in the ground state and in the first three excited singlet states, and indicates that there is at least one conical intersection, which is crucial for generation of excited-state molecules. A peroxy anion that is generated was found to be able to undergo a side reaction that leads to the same (isolated) product as in the light-generating reaction. These results demonstrate the applicability of 2-coumaranones as a model system for several bioluminescence reactions and may lead to the design of new 2-coumaranone derivatives with superior emission characteristics for bioanalytical applications.
AB - 2-Coumaranones are evolving as a new, efficient, versatile, and synthetically accessible platform for the next generation chemiluminescent probes. Despite the favorable quantum yields, the exact mechanism of their chemiluminescence remains elusive. Here, we analyze the details of the mechanism of the 2-coumaranone chemiluminescence using a combination of experimental and computational methods. By using EPR spectroscopy we show that superoxide radical anions are involved in the reactions, in support of the hypothesis that the mechanism includes a single electron transfer step. The decomposition of the high-energy intermediate, 1,2-dioxetanone, is described in the ground state and in the first three excited singlet states, and indicates that there is at least one conical intersection, which is crucial for generation of excited-state molecules. A peroxy anion that is generated was found to be able to undergo a side reaction that leads to the same (isolated) product as in the light-generating reaction. These results demonstrate the applicability of 2-coumaranones as a model system for several bioluminescence reactions and may lead to the design of new 2-coumaranone derivatives with superior emission characteristics for bioanalytical applications.
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U2 - 10.1039/c7cp03425c
DO - 10.1039/c7cp03425c
M3 - Article
C2 - 28812068
AN - SCOPUS:85028723143
SN - 1463-9076
VL - 19
SP - 22852
EP - 22859
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 34
ER -