title: Singlet oxygen generated from the decomposition of peroxymonocarbonate and its observation with chemiluminescence method.
abstract: The decomposition of peroxymonocarbonate (HCO(4)(-)) has been investigated by flow-injection chemiluminescence (CL) method. An ultraweak CL was observed during mixing the bicarbonate and hydrogen peroxide solution in organic cosolvent. An appropriate amount of fluorescent organic compounds, such as dichlorofluorescein (DCF), was added to the HCO(4)(-) solution, a strong CL was recorded. Based on studies of the spectrum of fluorescence, CL and UV-vis spectra, electron spin trapping (ESR) technique, mass spectra (MS) and comparison with H(2)O(2)/hypochlorite (ClO(-)) and H(2)O(2)/molybdate (MoO(4)(-)) systems, the CL mechanism was proposed. The reaction is initiated by unimolecular homolysis of the peroxo O-O bond in HO-OCOO(-) molecule. It was suggested that the bond rearrangement within radicals yield superoxide ion (O(2)(*-)). The interaction of superoxide ion with perhydroxyl radical produces singlet oxygen ((1)O(2)). The energy transfers from singlet oxygen to DCF forming an excited energy acceptor (DCF*). Luminescence (lambda(max)=509 nm) was emitted during the relaxation of the energy acceptor to the ground state.
authors.affiliation: The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China. jmlin@mail.tsinghua.edu.cn
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
authors.forename: Meilin
authors.initials: M
authors.lastname: Liu
mesh_terms: D000873:Anthracenes / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D017022:Flow Injection Analysis; D005456:Fluorescent Dyes / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008163:Luminescent Measurements / Q000379:methods*; D013058:Mass Spectrometry; D026082:Singlet Oxygen / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
chemical_list: D000873:Anthracenes; D002254:Carbonates; D003497:Cyclic N-Oxides; D005456:Fluorescent Dyes; D012997:Solvents; C512862:peroxycarbonic acid; D026082:Singlet Oxygen; C046961:9,10-diphenylanthracene; D006861:Hydrogen Peroxide; C003959:TEMPO