ABSTRACT
Benzyl alcohols and allylic alcohols were found to be oxidized to the corresponding aldehydes in the presence of a catalytic amount of iodine under irradiation of a fluorescent lamp.
Subject(s)
Alcohols , Aldehydes/chemical synthesis , Aldehydes/radiation effects , Allyl Compounds , Benzyl Compounds , Iodine/chemistry , Light , Alcohols/chemistry , Alcohols/radiation effects , Aldehydes/chemistry , Allyl Compounds/chemistry , Allyl Compounds/radiation effects , Benzyl Compounds/chemistry , Benzyl Compounds/radiation effects , Catalysis , Fluorescence , Molecular Structure , Oxidation-Reduction , StereoisomerismABSTRACT
The absolute gas phase ultraviolet absorption spectra of trichlorovinylsilane and allyltrichlorosilane have been measured from 191 to 220 nm. Over this region the absorption spectra of both species are broad and relatively featureless, and their cross sections increase with decreasing wavelength. The electronic transitions of trichlorovinylsilane were calculated by ab initio quantum chemical methods and the observed absorption bands assigned to the A(1)A''<-- X[combining tilde](1)A'' transition. The maximum absorption cross section in the region, at 191 nm, is sigma = (8.50 +/- 0.06) x 10(-18) cm(2) for trichlorovinylsilane and sigma = (2.10 +/- 0.02) x 10(-17) cm(2) for allyltrichlorosilane. The vinyl radical and the allyl radical are formed promptly from the 193 nm photolysis of their respective trichlorosilane precursors. By comparison of the transient visible absorption and the 1315 nm I atom absorption from 266 nm photolysis of vinyl iodide and allyl iodide, the absorption cross sections at 404 nm of vinyl radical ((2.9 +/- 0.4) x 10(-19) cm(2)) and allyl radical ((3.6 +/- 0.8) x 10(-19) cm(2)) were derived. These cross sections are in significant disagreement with literature values derived from kinetic modeling of allyl or vinyl radical self-reactions. Using these cross sections, the vinyl radical yield from trichlorovinylsilane was determined to be phi = (0.9 +/- 0.2) per 193 nm photon absorbed, and the allyl radical yield from allyltrichlorosilane phi = (0.7 +/- 0.2) per 193 nm photon absorbed.
Subject(s)
Acrylonitrile/chemistry , Allyl Compounds/chemistry , Photochemistry/methods , Silanes/chemistry , Ultraviolet Rays , Vinyl Compounds/chemistry , Acrylonitrile/radiation effects , Allyl Compounds/radiation effects , Free Radicals/chemistry , Free Radicals/radiation effects , Phase Transition/radiation effects , Photolysis/radiation effects , Silanes/radiation effects , Vinyl Compounds/radiation effectsABSTRACT
The objectives of this research work was to evaluate the reduction of THM precursors by cationic p-DADMAC and determine the correlations between the chlorine demand and trihalomethane formation in the presence of electrolyte solutions and ambient light. The chlorine demand was found to be significantly reduced provided that the H2SO4 electrolyte was fed to the sample solutions. The amount of CHCl3 formation was also decreased when the Na2SO4 electrolyte was introduced in spite of the levels of light intensity. The p-DADMAC can not only effectively remove the turbidity but also reduce the formation of CHCl3. The optimum dosage of p-DADMAC for reducing the turbidity, TOC and CHCl3 in the humic acid and source water samples was determined and depended upon the nature of organics.
