摘要:

AbstractA general numerical method and program for simulation of the kinetics of multistep reactions is described, with details for collation of data, construction of a mechanistic model, and simulation of reciprocal relaxation times and calculation of individual rate constants. The working scheme of the program includes an initial approximate simulation by adjustment of the rate constants followed by their optimization with a Powell minimization subroutine. The procedure is applied to aromatic nucleophilic addition.

ISSN:0538-8066    

DOI:10.1002/kin.550200302

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractFlash vacuum pyrolysis of (β‐chloro ethyl)‐pyrazole was studied. Pyrazole elimination and vinyl chloride formation were found. Competitive reactions with (β‐chloro ethyl)‐pyrazole were carried out using N‐ethyl‐3,5‐dimethyl pyrazole as internal standard to obtain the kinetic parameters (Ea). Δ(ΔH ƒ∘) for this r

ISSN:0538-8066    

DOI:10.1002/kin.550200303

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractWe present a kinetic study of atomic potassium in its electronic ground state, K(42S½), generated in the “single‐shot mode” by pulsed irradiation at elevated temperatures and monitored by time‐resolved atomic resonance absorption spectroscopy using the Rydberg doublet at λ = 404 nm (K[52PJ]←K[42S½]). Profiles for the decay of atomic potassium in the presence of various halogenated reactants were recorded at different temperatures, yielding the following Arrhenius parameters (kR=Aexp(−E/RT), errors 1σ):TextRA/10−10cm3molecule−1s−1E/kJmol−1Temp. RangeCH3F1.93+1.1−0.759±3.3822–922 KC2H5F1.40+2.5−0.962±6.6694–807 KC6H5F2.0+1.6−0.941±3.9705–812 KCH3Br1.7+0.3−0.215.9±1.2798–903 KHCl5.6+3.5−2.134.7±3.5828–902 KHBr1.9+0.3−0.334±1.2836–925 KA limited body of data is reported fork(K + C2H5Br) = 3.6 × 10−11cm3molecule−1s−1for the temperature range 704–733 K. These results for atomic potassium constitute a new body of absolute rate data which are compared with some previous results for reactions of atomic potassium with other reactants, and for reactions of atomic sodium, also determined by time‐resolved atomic resonance absorption spectroscopy. The data for HCl and HBr are final

ISSN:0538-8066    

DOI:10.1002/kin.550200304

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe kinetics and products of the homogeneous gas‐phase reactions of the OH radical with the chloroethenes were investigated at 298 ± 2 K and atmospheric pressure. Using a relative rate technique and ethane as a scavenger for the chlorine atoms produced in these OH radical reactions, rate constants (in units of 10−12cm3molecule−1s−1) of 8.11 ± 0.24, 2.38 ± 0.14, and 1.80 ± 0.03 were obtained for 1,1‐dichloroethene,cis‐1, 2‐dichloroethene andtrans‐1,2‐dichloroethene, respectively. Under these conditions, the major products observed by long pathlength FT‐IR absorption spectroscopy were HCHO and HC(O)Cl from vinyl chloride; HC(O)Cl fromcis‐ andtrans‐1,2‐dichloroethene; HCHO and COCl2from 1,1‐dichloroethene; HC(O)Cl and COCl2from trichloroethene; and COCl2from tetrachloroethene. In the absence of a Cl atom scavenger, significant yields of the chloroacetyl chlorides, CHxCl3−xC(O)Cl, were observed from 1,1‐dichloro‐, trichloro‐ and tetrachloroethene, indicating that these products resulted from reactions involving chlorine atoms. The yields of all of these products are reported and the mechanisms of these gas‐phase reactions discussed. In addition, OH radical reaction rate constants were redetermined, in the presence of a Cl atom scavenger, forcis‐ andtrans‐1,3‐dichloropropene and 3‐chloro‐2‐chloromethyl‐1‐propene, being (in units of 10−12cm3molecule

ISSN:0538-8066    

DOI:10.1002/kin.550200305

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550200301

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY