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  • 1
    Electronic Resource
    Electronic Resource
    Simultaneous laser absorption measurements of CN and OH in a shock tube study of HCN + OH → products (1995)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 1075-1087 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simultaneous, quantitative, narrow-line laser absorption measurements of CN time-histories at 388.444 nm and OH time-histories at 306.687 nm have been made in incident and reflected shock wave experiments using dilute mixtures of nitiric acid (HNO3) and HCN in argon. The thermal decomposition of HNO3 serves as a rapid source of OH upon shock-heating, and the OH subsequently reacts predominantly with the HCN in the test gas mixture. The rate coefficient for the reaction was determined in the temperature range 1120-1960 K via detailed kinetics modeling of the simultaneously acquired CN and OH measurements. These data are in good agreement with lower temperature measurements of the rate of the reverse reaction (-1a) when recent values of the heats of formation of CN and HCN are used. The expression \documentclass{article}\pagestyle{empty}\begin{document}$$ k_{1a} \, = \,3.90\, \times \,10^6 T^{1.83} \exp (- 5179/T)cm^3 mol^{ - 1} s^{ - 1}, $$\end{document} valid for temperatures 500 to 2000 K, effectively represents the experimental measurements. The estimated uncertainty of the expression for k1a is ±30%, based on the experimental uncertainties of the individual rate coefficient studies. Analysis of the decay region of the experimental OH time-histories yielded the total rate coefficient k1 (all product channels) for the reaction of HCN with OH for temperatures ranging from 1490 to 1950 K. These measurements are consistent with a previous theoretical analysis of the three primary addition-isomerization-dissociation processes for the HCN + OH reaction at combustion temperatures when the contribution to k1 from reaction (1a) is included. © 1995 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550271105
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  • 2
    Electronic Resource
    Electronic Resource
    A shock tube study of reactions of CN with HCN, OH, and H2 using CN and OH laser absorption (1996)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 28 (1996), S. 245-258 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantitative, narrow-line laser absorption measurements of CN time-histories at 388.444 nm were acquired in high-temperature pyrolysis and laser photolysis shock tube experiments. The data were analyzed using a detailed kinetics mechanism to determine the rate coefficients of the reactions $$\rm CN + OH\ \longrightarrow Products \eqno{(1)}$$ $$\rm CN + HCN \longrightarrow C_2N_2+H \eqno{(2)}$$ $$\rm CN + H_2\ \longrightarrow HCN+H \eqno{(3)}$$for temperatures between 940 and 1860 K. Two independent experimental approaches were utilized: laser photolysis (at 193 nm) of dilute C2N2/HCN/argon and C2N2/H2/argon mixtures in reflected shock wave experiments, and shock heating of HNO3/HCN/argon mixtures in incident and reflected shock wave experiments. Laser absorption measurements of OH at 306.687 nm were also taken in the HNO3/HCN/argon experiments The results are in good agreement with rate coefficient determinations from previous studies at different temperatures. The expression $$k_2=1.51\times 10^{7}\times T^{1.71}\exp(-770/T){\rm cm}^3\ {\rm mol}^{-1}\ s^{-1}\ \ \ (f=0.85, F=1.15),$$derived by Yang et al (1992) from their k2 measurements in combination with those of Szekely et al (1983), is recommended for the broad temperature range 300-3000 K. The uncertainty factors f and F give the limiting values of the rate coefficient kmin = f kbest fit, kmax = Fkbest fit. The recommended expression for the rate coefficient of reaction (3) $$k_3=2.95\times 10^{5}\times T^{2.45}\exp(-1126/T){\rm cm}^3\ {\rm mol}^{-1}\ s^{-1}\ \ \ (f=0.83, F=1.22),$$also valid for temperatures 300-3000 K, is taken from the transition state theory analysis of the CN + H2 reaction by Wagner and Bair (1986). The rate coefficient for reaction (1) was measured to be 4.0 × 1013cm3mol-1 s-1(f = 0.61, F = 1.40) for the temperature range 1250-1860 K. © 1996 John Wiley & Sons, Inc.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.2
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  • 3
    Electronic Resource
    Electronic Resource
    Solvation effects on the relative basicity of propylamines (1995)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 8 (1995), S. 26-30 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Slight structural moiecular variations are known to affect different properties of compounds. In solution, different solute-solvent interactions are known also to alter the properties of numerous compounds. Quantitative structure-activity relationships (QSAR) are used regularly to analyze and predict the variations of different properties of compounds that are caused by structural variations and significant solute-solvent interactions. The relative basicities of n-propylamine, dipro;ylamine and tripropylamine were determined in nine different solvents from potentiometric titrations. QSAR that were developed from these experimental basicity values were used to evaluate the type and significance of the solute-solvent interactions. The important interactions that influence basicity variations for the propylamines studied are dipolarity-polarizability interaction between the solute and the solvent and hydrogen bonds from the propylammonium ions to basic solvents. The role of hydrogen bonds from the propylamines to acidic solvents is minor.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610080106
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  • 4
    Electronic Resource
    Electronic Resource
    Reaction of phenoxy radical with nitric oxide (1995)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 8 (1995), S. 47-53 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The associationof C6H5O with NO was studied with the cavity-ring-down method by directly monitoring the decay of C6H5O in the presence of varying, excess amounts of NO. The biomolecular rate constant determined in the temperature range 297-373 K can be effectively rate constant determined in the temperature range 297-373 K can be effectively represented by k1 = 10- 12 · 12 ± 0.24e (194±185)/r cm3 molecule-1 with a negative activation energy of 0.8 kcal mol-1 (1 kcal = 4.184 kJ). In order to understand better the mechanism of the reaction, ab initio molecular orbital calculations were also carried out at the MP4(SDQ)/6-31G* level of theory using the HF optimized geometries. The molecular structues and energetics of five C6H5N1O2 isomers were calculated. Among them, the most likely and stable association product, phenyl nitrite (C4H5ONO), was found to be 17 kal mol-1 below the reactants, C6H5O + NO. Combining the measured rate constant and the calculated equilibrium constant for the association reaction, C6H5O + NO = C6H5ONO the rate constant for the unimolecular decomposition of C6H5ONO was obtained as k-1 = 4.6 × 1015E-8580/T s-1. The relatively large frequency factor suggests that a loose transition state was involved in the reaction, akin to those of its alkyl analogs (RONO, R = CH3, C2H5, etc.).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610080110
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  • 5
    Electronic Resource
    Electronic Resource
    Pressure and solvent effects on the kinetics of a Menshutkin reaction in aliphatic alcohols (1995)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 8 (1995), S. 63-70 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics of the Menshutkin reaction between triethylamine and iodoethane was studied at 313 K in seven primary and secondary alkanols. An accurate conductimetric method was employed to obtain second-order rate constants at pressures of 0·1-200 MPa. Volumes and isothermal compressions of activation were calculated by different model-based equations which are compared. Activation volumes at 0·1 MPa are in the range -26 to -33 cm3 mol-1. Procedures for dissecting intra- and intermolecular contributions to the volume of activation are discussed. A clear dependence of model parameters on the solvent volumetric properties was found.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610080202
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  • 6
    Electronic Resource
    Electronic Resource
    Synthetic and mechanistic aspects of anionic polymerization of (METH)acrylates initiated by metal-free salts of CH-acidic compounds (1995)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 8 (1995), S. 231-241 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The tetrabutylammonium salts of CH-acidic compounds (malonic acid diesters and diamides, nitropropane, phenylacetic and phenylpropionic acid esters and 9-ethyltfuorene) serve as inexpensive initiators for the anionic polymerization of acrylates and methacrylates at room temperature. Molecular weights of 1500-25,000 can be reached, the molecular weight distributions being fairly narrow (D = 1·1-1·4 in optimized cases). Side-reactions as monitored by GC analyses include backbiting and Hofmann elimination, which means that the process is not a true living polymerization. The x-ray structural analyses of the tetrabutylammonium salts of phenylacetic and 2-phenylpropionic and 2-phenylbutyric acid esters show that anions and cations interact with one another via hydrogen bonding. Therefore, the initiators cannot be considered to be naked anions, a conclusin which very likely also applies to the growing polymer chain end during polymerization.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610080406
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  • 7
    Electronic Resource
    Electronic Resource
    Kinetic study of the reaction of chlorine atoms with CF3I and the reactions of CF3 radicals with O2, Cl2 and NO at 296 K (1995)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 205-218 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the gas-phase reaction of Cl atoms with CF3I have been studied relative to the reaction of Cl atoms with CH4 over the temperature range 271-363 K. Using k(Cl + CH4) = 9.6 × 10-12 exp(-2680/RT) cm3 molecule-1 s-1, we derive k(Cl + CF3I) = 6.25 × 10-11 exp(-2970/RT) in which Ea has units of cal mol-1. CF3 radicals are produced from the reaction of Cl with CF3I in a yield which was indistinguishable from 100%. Other relative rate constant ratios measured at 296 K during these experiments were k(Cl + C2F5I)/k(Cl + CF3I) = 11.0 ± 0.6 and k(Cl + C2F5I)/k(Cl + C2H5Cl) = 0.49 ± 0.02. The reaction of CF3 radicals with Cl2 was studied relative to that with O2 at pressures from 4 to 700 torr of N2 diluent. By using the published absolute rate constants for k(CF3 + O2) at 1-10 torr to calibrate the pressure dependence of these relative rate constants, values of the low- and high-pressure limiting rate constants have been determined at 296 K using a Troe expression: k0(CF3 + O2) = (4.8 ± 1.2) × 10-29 cm6 molecule-2 s-1; k∞(CF3 + O2) = (3.95 ± 0.25) × 10-12 cm3 molecule-1 s-1; Fc = 0.46. The value of the rate constant k(CF3 + Cl2) was determined to be (3.5 ± 0.4) × 10-14 cm3 molecule-1 s-1 at 296 K. The reaction of Cl atoms with CF3I is a convenient way to prepare CF3 radicals for laboratory study. © 1995 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550270302
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  • 8
    Electronic Resource
    Electronic Resource
    Atmospheric chemistry of CF3COOH: Kinetics of fluorine and chlorine atom reaction at 295 ± 2 K (1995)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 189-194 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Using a relative rate technique the reactions of fluorine and chlorine atoms with CF3COOH have been determined to proceed with rate constants of (5.6 ± 0.7) × 10-11 and 〈1 × 10-17 cm3 molecule-1 s-1, respectively. Quoted errors for the F atom rate constant reflect statistical uncertainty (two standard deviations). Systematic errors could add an additional 20% uncertainty. Experiments were performed at 295 ± 2 K and 700 torr total pressure of nitrogen diluent. The reactions of Cl and F atoms with CF3COOH are of no atmospheric importance. Rainout is believed to be the dominant mechanism by which CF3COOH is removed from the atmosphere. The results from this study are discussed with respect to the design and interpretation of laboratory studies of the atmospheric chemistry of CFC replacements. © 1995 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550270209
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  • 9
    Electronic Resource
    Electronic Resource
    A shock tube study of methyl-methyl reactions between 1200 and 2400 K (1995)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 1179-1196 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The methyl-methyl reaction was studied in a shock tube using uv narrowline laser absorption to measure time-varying concentration profiles of CH3. Methyl radicals were rapidly formed initially by pyrolysis of various precursors, azomethane, ethane, or methyl iodide, dilute in argon. The contributions of the various product channels, C2H6, C2H5 + H, C2H4 + H2, and CH2 + CH4, were examined by varying reactant mixtures and temperature.The measured rate coefficients for recombination to C2H6 between 1200 and 1800 K are accurately fit using the unimolecular rate coefficients reported by Wagner and Wardlaw (1988). The rate coefficient for the C2H5 + H channel was found to be 2.4 (±0.5) × 1013 exp(-6480/T) [cm3/mol-s] between 1570 and 1780 K, and is in agreement with the value reported by Frank and Braun-Unkhoff (1988). No evidence of a contribution by the C2H4 + H2 channel was found in ethane/methane/argon mixtures, although methyl profiles in these mixtures should be particularly sensitive to this channel. An upper limit of approximately 1011 [cm3/mol-s] over the range 1700 to 2200 K was inferred for the rate coefficient of the C2H4 + H2 channel. Between 1800 and 2200 K, methyl radicals are also rapidly removed by CH3 + H ⇒ 1CH2 + H2. In this temperature range, the reverse reaction was found to have a rate coefficient of 1.3 (±0.3) × 1014 [cm3/mol-s], which is 1.8 times the room-temperature value. © 1995 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550271205
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  • 10
    Electronic Resource
    Electronic Resource
    Kinetics of vanadium (V) catalyzed oxidation of gallic acid by potassium bromate in acid medium (1996)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 28 (1996), S. 673-679 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of oxidation of gallic acid with potassium bromate in the presence of vanadium(V) catalyst in aqueous acid medium has been studied under varying conditions. The active species of catalyst and oxidant in the reaction were understood to be HBrO3 and VO2+. The autocatalysis exhibited by one of the products, i.e. Br-, was attributed to complex formation between bromide and vanadium(V). A composite scheme and rate law were possible, some reaction constants involved in the mechanism have been evaluated. © 1996 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.5
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