Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Chemiluminescence from

Irvin J A and Dagdigian P J 1980 Chemiluminescence from the Ca(4s3d D) + O2 reaction absolute cross sections, photon yield, and CaO dissociation energy J. Chem. Rhys. 73 176-82... [Pg.2086]

A number of chemiluminescent reactions may proceed through unstable dioxetane intermediates (12,43). For example, the classical chemiluminescent reactions of lophine [484-47-9] (18), lucigenin [2315-97-7] (20), and transannular peroxide decomposition. Classical chemiluminescence from lophine (18), where R = CgH, is derived from its reaction with oxygen in aqueous alkaline dimethyl sulfoxide or by reaction with hydrogen peroxide and a cooxidant such as sodium hypochlorite or potassium ferricyanide (44). The hydroperoxide (19) has been isolated and independentiy emits light in basic ethanol (45). [Pg.265]

Classical chemiluminescence from lucigenin (20) is obtained from its reaction with hydrogen peroxide in water at a pH of about 10 Qc is reported to be about 0.5% based on lucigenin, but 1.6% based on the product A/-methylacridone which is formed in low yield (46). Lucigenin dioxetane (17) has been prepared by singlet oxygen addition to an electron-rich olefin (16) at low temperature (47). Thermal decomposition of (17) gives of 1.6% (47). [Pg.265]

Dioxetane decomposition has also been proposed to account for chemiluminescence from other reactions (43), including gas-phase reactions of singlet oxygen with ethylene and vinyl ethers (53). [Pg.265]

The first detailed investigation of the reaction kinetics was reported in 1984 (68). The reaction of bis(pentachlorophenyl) oxalate [1173-75-7] (PCPO) and hydrogen peroxide cataly2ed by sodium saUcylate in chlorobenzene produced chemiluminescence from diphenylamine (DPA) as a simple time—intensity profile from which a chemiluminescence decay rate constant could be determined. These studies demonstrated a first-order dependence for both PCPO and hydrogen peroxide and a zero-order dependence on the fluorescer in accord with an earher study (9). Furthermore, the chemiluminescence quantum efficiencies Qc) are dependent on the ease of oxidation of the fluorescer, an unstable, short-hved intermediate (r = 0.5 /is) serves as the chemical activator, and such a short-hved species "is not consistent with attempts to identify a relatively stable dioxetane as the intermediate" (68). [Pg.266]

Luminol (Phthalhydrazide). Chemiluminescence from luminol [521-31-3] (3-aminophthalhydrazide) (29), isoluminol [3682-14-2] (4-aminophthalhydrazide), and analogues has been studied extensively (104—106). [Pg.268]

Most likely singlet oxygen is also responsible for the red chemiluminescence observed in the reaction of pyrogaHol with formaldehyde and hydrogen peroxide in aqueous alkaU (152). It is also involved in chemiluminescence from the decomposition of secondary dialkyl peroxides and hydroperoxides (153), although triplet carbonyl products appear to be the emitting species (132). [Pg.270]

Electronic excitation from atom-transfer reactions appears to be relatively uncommon, with most such reactions producing chemiluminescence from vibrationaHy excited ground states (188—191). Examples include reactions of oxygen atoms with carbon disulfide (190), acetylene (191), or methylene (190), all of which produce emission from vibrationaHy excited carbon monoxide. When such reactions are carried out at very low pressure (13 mPa (lO " torr)), energy transfer is diminished, as with molecular beam experiments, so that the distribution of vibrational and rotational energies in the products can be discerned (189). Laser emission at 5 p.m has been obtained from the reaction of methylene and oxygen initiated by flash photolysis of a mixture of SO2, 2 2 6 (1 )-... [Pg.271]

Divalent copper, cobalt, nickel, and vanadyl ions promote chemiluminescence from the luminol—hydrogen peroxide reaction, which can be used to determine these metals to concentrations of 1—10 ppb (272,273). The light intensity is generally linear with metal concentration of 10 to 10 M range (272). Manganese(II) can also be determined when an amine is added to increase its reduction potential by stabili2ing Mn (ITT) (272). Since all of these ions are active, ion exchange must be used for deterrnination of a particular metal in mixtures (274). [Pg.274]

Totsune, H., Nakano, M., and Inaba, H. (1993). Chemiluminescence from bamboo shoot cut. Biochem. Biophys. Res. Commun. 194 1025-1029. [Pg.444]

Zou G, Ju H (2004) Electrogenerated chemiluminescence from a CdSe nanocrystal film and its sensing application in aqueous solution. Anal Chem 76 6871-6876... [Pg.350]

Emission from dimols of singlet oxygen may be detected by photomultipliers used for measurement of chemiluminescence from hydrocarbon polymers with a maximum spectral sensitivity at 460 nm. The above scheme, however, requires the presence of at least one molecule of hydrogen peroxide in close vicinity to the two recombining peroxyl radicals and assumes a large heterogeneity of the oxidation process. [Pg.465]

Figure 9 Isothermal chemiluminescence from oxidation of dicaproyl hexamethylene diamide CH3-(CH2)4CONH-(CH2)6-NHCO-(CH2)4-CH3 (model of polyamide) in oxygen. Figure 9 Isothermal chemiluminescence from oxidation of dicaproyl hexamethylene diamide CH3-(CH2)4CONH-(CH2)6-NHCO-(CH2)4-CH3 (model of polyamide) in oxygen.
Figure 19 Chemiluminescence from oxidation of polypropylene containing 0.5 % wt. of Irganox 1010 at 150°C in oxygen. Line 1 represents the original polymer film line 2 is the same sample after 7,890 s of annealing at 130°C. Figure 19 Chemiluminescence from oxidation of polypropylene containing 0.5 % wt. of Irganox 1010 at 150°C in oxygen. Line 1 represents the original polymer film line 2 is the same sample after 7,890 s of annealing at 130°C.
Figure 21 Chemiluminescence from polybutadiene the effect of oxygen concentration in a mixture with nitrogen, 130°C, total flow of gas 3.6 l/h, the numbers denote the volume percent of oxygen in the mixture with nitrogen. Figure 21 Chemiluminescence from polybutadiene the effect of oxygen concentration in a mixture with nitrogen, 130°C, total flow of gas 3.6 l/h, the numbers denote the volume percent of oxygen in the mixture with nitrogen.
J. Rychly and L. Rychla, Chemiluminescence from polymers. In M. Strlic and J. Kolar (Eds.), Ageing and Stabilisation of Paper, National and University Library, Ljubljana, Slovenia, 2005, p. 71. [Pg.496]

Special review articles published since 1968 on these topics are one by E. H. White and D. F. Roswell 2> on hydrazide chemiluminescence M. M. Rauhut 3) on the chemiluminescence of concerted peroxide-decomposition reactions and D. M. Hercules 4 5> on chemiluminescence from electron-transfer reactions. The rapid development in these special fields justifies a further attempt to depict the current status. Results of bioluminescence research will not be included in this article except for a few special cases, e.g. enzyme-catalyzed chemiluminescence of luminol, and firefly bioluminescence 6>. [Pg.66]

Chemiluminescence from lucigenin is observed even without the catalytic transition metal ions but it is more intense when these ions are used. In aqueous or predominately aqueous solutions the CL yield is 0.01-0.02, which makes it a slightly better emitter than luminol [35], The emission of lucigenin is also catalyzed by Pb(II), Bi(III), Tl(III), and Hg(I) ions, which do not catalyze the CL of luminol [36],... [Pg.112]

These studies have allowed the spectroscopic identification of a number of electronically excited states of the metal oxides, but there appear to have been no analytical applications of the reactions to date. The emitting states, as summarized by Toby [14], are CaO(A n), SrO(ATl), PbO(a32+, b32+), ScO(C2II), YO(C2n), FcO(C ), A10(A2ni B2X+), and BaO(A i)1, D 2+). Nickel carbonyl reacts with ozone to produce chemiluminescence from an excited electronic state of NiO, which is probably produced in the Ni + 03 reaction [42, 43],... [Pg.359]

Low-pressure discharges tend to produce much more intense chemiluminescence from alkenes than from alkanes. This has been attributed to the addition of N to the double bond, as illustrated for ethylene,... [Pg.363]

It has been proposed that this reaction intermediate could decompose to produce HCN and CH3 [55], Chemiluminescence from alkanes can be greatly enhanced by addition of HC1. The proposed explanation is that energy transfer from active nitrogen dissociates HC1 to produce chlorine atoms, which have rapid hydrogen-atom abstraction reactions with alkanes,... [Pg.364]

Birks et al. reported chemiluminescence from the A3n0+ and B3 states of IF in the reaction of F2 with I2 and suggested that the reaction kinetics were consistent with a four-center reaction forming the products IF + IF [74], In a series of molecular beam studies, it was shown that the reaction actually forms a collision complex that decomposes to form two sets of products, IF + IF and I2F + F [75-77] ... [Pg.372]


See other pages where Chemiluminescence from is mentioned: [Pg.46]    [Pg.46]    [Pg.115]    [Pg.330]    [Pg.494]    [Pg.530]    [Pg.577]    [Pg.579]    [Pg.580]    [Pg.976]    [Pg.269]    [Pg.276]    [Pg.5]    [Pg.172]    [Pg.342]    [Pg.451]    [Pg.463]    [Pg.464]    [Pg.466]    [Pg.468]    [Pg.469]    [Pg.471]    [Pg.488]    [Pg.490]    [Pg.493]    [Pg.494]    [Pg.495]    [Pg.495]   
See also in sourсe #XX -- [ Pg.123 ]




SEARCH



© 2024 chempedia.info