One of the first descriptions found in the literature about a chemiluminescent reaction is the autoxidation of lophine, reported by Radziszewski in 1877. It is postulated that the lophine reaction with oxygen in the presence of a strong base, leads to the formation of a hydroperoxide, which undergoes a base-induced cyclization generating a 1,2-dioxetane intermediate. The decomposition of this cyclic peroxide leads to the singlet excited state of an amidine, which decays to the ground state by fluorescence, emitting an intense yellow light. The oxidation reaction of lophine and its derivatives has been studied previously, but a deeper understanding about the mechanism operating in this interesting reaction is still yet to be acquired. This project proposes to carry out a detailed study of the mechanism that acts in the formation of emitting excited states for such transformation. As such, hydroperoxides with different substituents on the aromatic rings will be synthesized from the photooxygenation of their corresponding lophine derivatives. The hydroperoxides will be protected with a t-butyldimethylsilyl group, in order to obtain the silylperoxides derivatives. Also, hydroperoxides and silylperoxides containing a hydroxyl group as a substituent at the ortho, meta and para positions will be prepared. Kinetic studies of the chemiluminescence emission will be performed, inducing the decomposition of hydroperoxides with different bases and of silylperoxides with fluoride. Thus, it will be investigated the effect of substituents on the kinetics and singlet excited state formation quantum yields of the induced decomposition of these peroxides.
News published in Agência FAPESP Newsletter about the scholarship:
BARTOLONI, FERNANDO HEERING;
DE LA FUENTE-NUNEZ, CESAR.
Light-Emitting Probes for Labeling Peptides.
CELL REPORTS PHYSICAL SCIENCE,
DEC 23 2020.
Web of Science Citations: 1.