High-temperature photochemistry kinetics studies of the reactions of H(1(2)s) and D(1(2)S) with N sub 2 O

Technical Report · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5553826

Fontijn, A; Marshall, P; Ko, T

The H + N{sub 2}O and D + N{sub 2}O reactions have been investigated by using the high-temperature photochemistry (HTP) technique. Empirical fits to the pressure-independent rate coefficients yield k1(T) = 4.2 x 10 to the -10th to the -14th power exp(-2290 K/T)+ 3.7 x 10 to the -10th power exp (-8430 K/T) and K2 (T) = 3.5x 10 to the 13th power exp -3600 K/T + 5.3 x 10 to the 10th powder exp(9-9170 K/T) cc/molecule/s over the ranges 410-1230 and 450-1210 K, respectively. The pi precision of these results is better than 11% and the 95% accuracy limits are assessed at about + or - 25%. The kinetic isotope effect x(T) = k1(T)/k2(T) decreases from 2.2 at 450 K to 1.3 at 1200 K, behavior contrary to classical transition-state theory which predicts x(T) increasing with temperature. The data are qualitatively consistent with a rate-controlling step that is dominated by tunneling at the lower end of the temperature range.

• Research Organization: Rensselaer Polytechnic Inst., Troy, NY (USA)
• OSTI ID: 5553826
• Report Number(s): AD-A-209372/2/XAB
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400500* -- Photochemistry
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
DEUTERIUM
ELEMENTS
HIGH TEMPERATURE
HYDROGEN
HYDROGEN ISOTOPES
ISOTOPES
KINETICS
LIGHT NUCLEI
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
REACTION KINETICS
STABLE ISOTOPES