摘要:

AbstractThe reaction between tris(acetylacetonato)magnanese(III) and hexa(N,N‐dimethylformamide)iron(III) perchlorate in acetonitrile proceeds in two stages. The first stage corresponds to the reaction of pentacoordinated Fe(DMF) 53+with Mn(acac)3, and the rate‐determining step of the second stage consists mainly in the elimination of a DMF ligand from Fe(DMF) 63+to yield Fe(DMF) 53+which reacts rapidly with the manganese complex. The formation of Fe(DMF) 53+is catalyzed by Mn(acac)3, this catalytic effect being decreased by manganese products. The rate‐determining step for the formation of Fe(acac)3is the transfer of the first acetylacetonate to yield Fe(acac)2+. The final products of iron depend on the ratio of reactant concentrations. With Mn or Fe in excess, Fe(acac)3or Fe(acac)2+are ma

ISSN:0538-8066    

DOI:10.1002/kin.550110102

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe thermal decomposition of cyclobutyl chloride has been investigated over the temperature range of 892–1150 K using the technique of very low‐pressure pyrolysis (VLPP). The reaction proceeds via two competitive unimolecular channels, one to yield ethylene and vinyl chloride and the other to yield 1,3‐butadiene and hydrogen chloride, with the latter being the major reaction under the experimental conditions. With the usual assumption that gas‐wall collisions are «strong,» RRKM calculations, generalized to take into account two competing pathways, show that the experimental unimolecular rate constants are consistent with the high‐pressure Arrhenius parameters given by logk1(sec−1) = (14.8 ± 0.3) − (61.1 ± 1.0)/Θ for vinyl chloride formation and logk2(sec−1) = (13.6 ± 0.3) − (55.7 ± 1.0)/Θ for 1,3‐butadiene formation, where Θ = 2.303RTkcal/mol. TheAfactors were assigned from previous high‐pressure low‐temperature data of other workers assuming a four‐center transition state for 1,2‐HCl elimination and a chlorine‐bridged biradical transition state for vinyl chloride formation. The activation energies are in good agreement with the high‐pressure results which were obtained with a conventional static system. The differe

ISSN:0538-8066    

DOI:10.1002/kin.550110103

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe decomposition of C2H6in Ar was studied by laser‐absorption and laser‐schlieren measurements of the reaction rate behind incident shock waves with 1300

ISSN:0538-8066    

DOI:10.1002/kin.550110104

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY

摘要:

AbstractA detailed mechanism is presented for reactions occurring during irradiation of part‐per‐million concentrations of propene and/orn‐butane and oxides of nitrogen in air. Data from an extensive series of well‐characterized smog chamber experiments carried out in our 5800‐liter evacuable chamber–solar simulator facility designed for providing data suitable for quantitative model validation were used to elucidate several unknown or uncertain kinetic parameters and details of the reaction mechanism.The mechanism was then tested against the data base from the smog chamber runs. In general, most calculated concentration–time profiles agreed with experiments to within the experimental uncertainties. Fits were usually attained to within ∼±20% or better for ozone, NO, propene, andn‐butane, to within ∼±30% or better for NO2, PAN, methyl ethyl ketone, 2‐butyl nitrate, butyraldehyde, and (in runs not containing propene) methyl nitrate, to within ⋐±50% or better for the minor products 1‐butyl nitrate and propene oxide, and to within a factor of 2 for methyl nitrate in propene‐containing runs. Propionaldehyde was consistently underpredicted in all runs; it is probably a chamber contaminant. For formaldehyde and acetaldehyde, the major products in both systems, fits to within ⋐±20% were often obtained, yet for a number of experiments, significantly greater discrepancies were observed, probably as a result of experimental and/or analytical problems.The good fits to experimental data were attained only after adjusting several rate constants or rate constant ratios related to uncertainties concerning chamber effects or the chemical mechanism. The largest uncertainty concerns the necessity to include in the mechanism a significant rate of radical input from unknown sources in the smog chamber. Other areas where fundamental kinetic and mechanistic data are most needed before a predictive, detailed propene +n‐butane‐NOx‐air smog model can be completely validated concern other chamber effects, the O3+ propene mechanism, decomposition rates of substituted alkoxy radicals, primary quantum yields for radical production as a function of wavelength for aldehyde and ketone photolyses, and the mechanisms and rates of react

ISSN:0538-8066    

DOI:10.1002/kin.550110105

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550110106

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550110107

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550110101

出版商:John Wiley&Sons, Inc.    

年代:1979

数据来源: WILEY