Carbonate-catalyzed chemiluminescence decomposition of peroxynitrite via (CO2)2∗ intermediate

Abstract

Peroxynitrous acid (ONOOH) was formed by the on-line rapid reaction of acidified hydrogen peroxide with nitrite in a simple flow system. A weak chemiluminescent (CL) signal was observed due to the production of singlet oxygen ( 1 O 2 ) when ONOOH reacted with NaOH, whereas the replacement of NaOH by Na 2 CO 3 markedly enhanced the CL intensity. The predominant CL-enhanced pathway was achieved by the carbonate-catalyzed decomposition of peroxynitrite (ONOO − ). Carbonate species was regenerated in the process, that is, carbonate acts as a catalyst. Based on the studies of CL and fluorescence spectra, a possible CL mechanism from the reaction of carbonate with ONOOH was proposed. In brief, ONOOH was an unstable compound in acidic solution and could be quenched into ONOO − in basic media. It was suggested that ONOO − reaction with excess HCO 3 − proceeded via one-electron transfer to yield bicarbonate ion radicals (HCO 3 • ). The recombination of HCO 3 • may directly generate excited triplet dimers of two CO 2 molecules [(CO 2 ) * 2 ]. With the decomposition of this unstable intermediate to CO 2 , the energy was released by CL emission. The addition of uranine into carbonate solution caused enhancement of the CL signal, which was due to a part of excited triplet dimers of two CO 2 molecules energy to transfer to uranine, resulting in two CL peaks.

Enhanced chemiluminescence of peroxomonosulfate–cobalt (II) system in the presence of dicarboxylic acids

“…In about 1 × 10 −8 s, ( 1 O 2 ) 2 * decayed quickly to O 2 with energy state decayed from excited state to the ground state. The CL emission from the decay formed the CL signal with emission bands in the VIS region: at around 545, 580, 634 and 703 nm [reaction (18)] (26).…”

“…Generally, most CL methods involve only a few chemical components to actually generate light emission. Inorganic oxidants, such as peroxomonosulfate (HSO 5 ‐ ), persulfate (S 2 O 8 2− ), peroxymonocarbonate (HCO 4 ‐ ) and peroxynitrite (ONOO ‐ ), are the chemical components usually used in CL systems (17,18). For instance, Amir reported a flow injection method for the determination of l ‐cysteine, based on its enhancement of CL emission of luminol oxidized by sodium persulfate in alkaline solution (19).…”

Utilizing of Ag@AgCl@graphene oxide@Fe3O4 nanocomposite as a magnetic plasmonic nanophotocatalyst in light-initiated H2O2 generation and chemiluminescence detection of nitrite

“…So, uranine was added into the carbonate solution as a sensitizer. The CL emission band at 500-550 nm can be considered as a result of intermolecular energy transfer in that the part of energy from the (CO 2 ) 2 * is transferred to uranine [37,38]. Since the uranine has high quantum efficiency, more photons are emitted showing the good CL intensity.…”

Chemiluminescence behavior of sodium hydrogen carbonate in the potassium permanganate-hydrogen peroxide reaction

“…The decomposition energy of (CO 2 ) 2 dimer was calculated by the EHMO method and found to be 132 kcal mol/L, which was high enough to promote emission at a wavelength higher than 220 nm [42]. The peak at 634 nm resulted from the emission spectra of 1 O 2 [43]. It has higher energy and loses its excess energy by luminescence.…”