Kinetics of OH Reactions with N2H4, CH3NHNH2 and (CH3)2NNH2 in the Gas Phase
Abstract
The gas phase reaction kinetics of OH with three di-amine rocket fuels; N(2)H(4), CH(3)NHNH(2) and (CH3)2NNH2 was studied in a discharge flow-tube apparatus and a pulsed- photolysfs reactor under pseudo-first-order conditions in OH. Direct laser-induced fluorescence monitoring 9f the OH temporal profiles in a known excess of the DI-AMINE yielded the following absolute second-order OH rate coefficient expressions; k(I) = (2.17 plus or minus 0.39) x 10(exp -11) e(160 plus or minus 30)/T, k(2) = (4.59 plus or minus 0.83) x 10(exp -11) e(85 plus or minus 35)/T and k(3) = (3.35 plus or minus 0.60) x 10(exp -11) e(175 plus or minus 25)/T cu cm molec-1 s(-1), respectively, for reactions with N(2)H(4), CH(3)NHNH(2) and (CH3)(2)NNH(2) in the temperature range 232-637 K. All three reactions did not show any discemable pressure dependence on He or N(2) buffer gas pressure of up to 530 torr. The magnitude, and the weak temperature and the lack of pressure effects of the OH + N(2)H(4) reaction rate coefficient suggests that a simple direct metathesis of H-atom may not be important compared to addition of the OH to one of the N-centers of the di-amine skeleton, followed by rapid dissociation of the intermediate into products. Our findings on this reaction are qualitatively consistent with a previous ab-initio study Armstrong et al. J Phys Chem A 1997, 101, 4761. However, in the alkylated di-amines, direct H-abstraction from the methyl moiety can not be completely ruled out.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 25, 2000
- Accession Number
- ADA409315
Entities
People
- Ghanshyam L Vaghjiani
Organizations
- Air Force Research Laboratory