TY - JOUR

T1 - First rate constants reactions of OH radicals with amides

AU - Koch, Robert

AU - Palm, Wolf-Ulrich

AU - Zetzsch, Cornelius

PY - 1997

Y1 - 1997

N2 - Rate constants have been measured for the reaction of OH radicals with four amides, R1N(CH3)-C(O)R2 (R1 = H or Methyl, R2 = Methyl or Ethyl), at 300 and 384 K using flash photolysis/resonance fluorescence. Reactants are introduced under slow flow conditions and are controlled by two independent methods, gas saturation and continuous injection. It turns out that the reactivities of the amides are considerably lower than those of the corresponding amines. The pattern of rate constants obtained at 300 K: 14, 21, 5.2, and 7.6 · 10-12 cm3/s for N,N-Dimethylacetamide (dmaa), N,N-Dimethylpropionamide (dmpa), N-Methylacetamide (maa), and N-Methylpropionamide (mpa), respectively, indicates a single, dominating reaction center and strong electronic effects of the substituents at both sides of the amide function. Correspondingly, the observed negative temperature dependence (E/R= - 400 to - 600 K) excludes a direct abstraction mechanism.

AB - Rate constants have been measured for the reaction of OH radicals with four amides, R1N(CH3)-C(O)R2 (R1 = H or Methyl, R2 = Methyl or Ethyl), at 300 and 384 K using flash photolysis/resonance fluorescence. Reactants are introduced under slow flow conditions and are controlled by two independent methods, gas saturation and continuous injection. It turns out that the reactivities of the amides are considerably lower than those of the corresponding amines. The pattern of rate constants obtained at 300 K: 14, 21, 5.2, and 7.6 · 10-12 cm3/s for N,N-Dimethylacetamide (dmaa), N,N-Dimethylpropionamide (dmpa), N-Methylacetamide (maa), and N-Methylpropionamide (mpa), respectively, indicates a single, dominating reaction center and strong electronic effects of the substituents at both sides of the amide function. Correspondingly, the observed negative temperature dependence (E/R= - 400 to - 600 K) excludes a direct abstraction mechanism.

KW - Chemistry

UR - http://www.scopus.com/inward/record.url?scp=0031078701&partnerID=8YFLogxK

U2 - 10.1002/(sici)1097-4601(1997)29:2<81::aid-kin1>3.0.co;2-g

DO - 10.1002/(sici)1097-4601(1997)29:2<81::aid-kin1>3.0.co;2-g

M3 - Journal articles

AN - SCOPUS:0031078701

VL - 29

SP - 81

EP - 87

JO - International Journal of Chemical Kinetics

JF - International Journal of Chemical Kinetics

SN - 0538-8066

IS - 2

ER -