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Flores JA Andino JG Tsvetkov NP Pink M Wolfe RJ Head AR Lichtenberger DL Massa J Caulton KG 《Inorganic chemistry》2011,50(17):8121-8131
The ligand class 2,2'-pyridylpyrrolide is surveyed, both for its structural features and its electronic structure, when attached to monovalent K, Cu, Ag, Au, and Rh. The influence of pyrrolide ring substituents is studied, as well as the question of push/pull interaction between the pyridyl and pyrrolide halves. The π donor ability of the pyrrolide is found to be less than that of an analogous phenyl. However, in contrast to the phenyl analog, the HOMO is pyrrolide π in character for pyridylpyrrolide complexes of copper and rhodium, while it is conventionally metal localized for planar, d(8) rhodium pyridylphenyl. Monovalent three-coordinate copper complexes show great deviations from Y-shaped toward T-shaped structures, including cases where the pyridyl ligand bonds only weakly. 相似文献
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The ultraviolet absorption spectrum of the neopentyl peroxy radical (CH3)3CCH2O2, and the kinetics and products of its self reaction have been studied in the gas phase at 298 K. Absorption cross sections were quantified over the wavelength range 230–290 nm. The measured cross section at 250 nm was; Errors represent statistical (2σ) together with our estimate of potential systematic errors(15%). The kinetics of the decay of the UV absorption following the generation of the neopentyl peroxy radicals was complicated by the rapid decomposition of the (CH3)3CCH2O radicals formed in channel (4a). By measuring the yield of t-butyl peroxy radicals, the branching ratio k4a/(k4a + k4b) was determined to be 0.39 ± 0.03. The rate constant for the self reaction of neopentyl peroxy radicals was k4 = (1.07 ± 0.22) × 10?12 cm3 molecule?1 s?1. Quoted errors represent 2σ. These results are discussed with respect to the available literature data. © John Wiley & Sons, Inc. 相似文献
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Using Fourier transform infrared spectroscopy, the ethene yield from the reaction of C2H5 radicals with O2 has been determined to be 1.50 ± 0.09%, 0.85 ± 0.11%, and <0.1% at total pressures of 25, 50, and 700 torr, respectively. Additionally, the rate constant of the reaction of C2H5 radicals with molecular chlorine was measured relative to that with molecular oxygen. (1) A ratio k6/k7 = 1.99 ± 0.14 was measured at 700 torr total pressure which, together with the literature value of k7 = 4.4 × 10?12 cm3 molecule?1s?1, yields k6 = (8.8 ± 0.6) × 10?12 cm3 molecule?1s?1. Quoted errors represent 2σ. These results are discussed with respect to previous kinetic and mechanistic studies of C2H5 radicals. 相似文献
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The effects of ammonium sulfate aerosols on the kinetics of the hydroxyl radical reactions with C1–C6 aliphatic alcohols have been investigated using the relative rate technique. P‐xylene was used as a reference compound for the C2–C6 aliphatic alcohols study, and ethanol was used as a reference compound for the methanol study. Two different aerosol concentrations that are typical of polluted urban conditions were tested. The total surface areas of aerosols were 1400 μm2 cm?3 (condition I) and 3400 μm2 cm?3 (condition II). Results indicate that ammonium sulfate aerosols promote the ethanol/OH radical and 1‐propanol/OH radical reactions as compared to the p‐xylene/OH radical reaction. The relative rate of the ethanol/·OH reaction versus the p‐xylene/·OH reaction increased from 0.19 ± 0.01 in the absence of aerosols to 0.24 ± 0.01 and 0.26 ± 0.02 under aerosol conditions I and II, respectively. The relative rate of the 1‐propanol/·OH reaction versus the p‐xylene/·OH reaction increased from 0.45 ± 0.03 in the absence aerosols to 0.56 ± 0.02 and 0.55 ± 0.03 under aerosol conditions I and II, respectively. However, significant changes in the relative rates of the 1‐butanol/·OH, 1‐pentanol/·OH, and 1‐hexanol/·OH reactions versus the p‐xylene/·OH reaction were not observed for either aerosol concentration. The relative rates of the methanol/·OH reaction versus the ethanol/·OH reaction were identical in the absence and presence of aerosols. These results indicate that ammonium sulfate aerosols promote the methanol/·OH reaction as much as the ethanol/·OH reaction (as compared to the p‐xylene/·OH reaction). © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 422–430, 2001 相似文献
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Dorothy H. Gibson Jianguo Wu Jose G. Andino Mark S. Mashuta 《Journal of chemical crystallography》2006,36(11):769-775
The first titled compound, 1, was obtained by treating [Ru(bpy)(η2-tpy)(CO)CH2OH]PF6 with acetic anhydride. Heating 1 in acetonitrile afforded 2, [Ru((η3-tpy)(MeCN)(CO) CH2OAc]PF6. Allowing 2 to stand in CH2Cl2 followed by concentration and precipitation afforded the second titled compound, 3 ([Ru((η3-tpy)(CO)–CH2OAc]PF6), in which the acetoxymethyl group had become bidentate. Crystal data for 1, monoclinic crystal system, space group C2/c, a=26.001(4) ?, b=13.0395(18) ?, c=20.718(3) ?, β=107.700(2)°, V=6691.7(16) ?3, Z=8; for 3, monoclinic crystal system, space group P21/n, a=10.864(2) ?, b=16.922(4) ?, c=11.127(2) ?, β=90.907(3)°, V=2045.4(8) ?3, Z=4. 相似文献
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Tingting Gao Jean M. Andino Carlos C. Rivera Misaela Francisco Márquez 《国际化学动力学杂志》2009,41(7):483-489
The rate constants of the gas‐phase reaction of OH radicals with trans‐2‐hexenal, trans‐2‐octenal, and trans‐2‐nonenal were determined at 298 ± 2 K and atmospheric pressure using the relative rate technique. Two reference compounds were selected for each rate constant determination. The relative rates of OH + trans‐2‐hexenal versus OH + 2‐methyl‐2‐butene and β‐pinene were 0.452 ± 0.054 and 0.530 ± 0.036, respectively. These results yielded an average rate constant for OH + trans‐2‐hexenal of (39.3 ± 1.7) × 10?12 cm3 molecule?1 s?1. The relative rates of OH+trans‐2‐octenal versus the OH reaction with butanal and β‐pinene were 1.65 ± 0.08 and 0.527 ± 0.032, yielding an average rate constant for OH + trans‐2‐octenal of (40.5 ± 2.5) × 10?12 cm3 molecule?1 s?1. The relative rates of OH+trans‐2‐nonenal versus OH+ butanal and OH + trans‐2‐hexenal were 1.77 ± 0.08 and 1.09 ± 0.06, resulting in an average rate constant for OH + trans‐2‐nonenal of (43.5 ± 3.0) × 10?12 cm3 molecule?1 s?1. In all cases, the errors represent 2σ (95% confidential level) and the calculated rate constants do not include the error associated with the rate constant of the OH reaction with the reference compounds. The rate constants for the hydroxyl radical reactions of a series of trans‐2‐aldehydes were compared with the values estimated using the structure activity relationship. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 483–489, 2009 相似文献
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