TY - JOUR
T1 - Ab initio chemical kinetics for the hydrolysis of N2O 4 isomers in the gas phase
AU - Zhu, R. S.
AU - Lai, Ke Yu
AU - Lin, Ming-Chang
PY - 2012/5/10
Y1 - 2012/5/10
N2 - The mechanism and kinetics for the gas-phase hydrolysis of N 2O4 isomers have been investigated at the CCSD(T)/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p) level of theory in conjunction with statistical rate constant calculations. Calculated results show that the contribution from the commonly assumed redox reaction of sym-N2O 4 to the homogeneous gas-phase hydrolysis of NO2 can be unequivocally ruled out due to the high barrier (37.6 kcal/mol) involved; instead, t-ONONO2 directly formed by the association of 2NO 2, was found to play the key role in the hydrolysis process. The kinetics for the hydrolysis reaction, 2NO2 + H2O HONO + HNO3 (A) can be quatitatively interpreted by the two step mechanism: 2NO2 → t-ONONO2, t-ONONO2 + H2O → HONO + HNO3. The predicted total forward and reverse rate constants for reaction (A), ktf = 5.36 ×10-50T 3.95exp(1825/T) cm6 molecule-2 s-1 and ktr = 3.31 ×10-19T2.478exp(-3199/T) cm3 molecule-1 s-1, respectively, in the temperature range 200-2500 K, are in good agreement with the available experimental data.
AB - The mechanism and kinetics for the gas-phase hydrolysis of N 2O4 isomers have been investigated at the CCSD(T)/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p) level of theory in conjunction with statistical rate constant calculations. Calculated results show that the contribution from the commonly assumed redox reaction of sym-N2O 4 to the homogeneous gas-phase hydrolysis of NO2 can be unequivocally ruled out due to the high barrier (37.6 kcal/mol) involved; instead, t-ONONO2 directly formed by the association of 2NO 2, was found to play the key role in the hydrolysis process. The kinetics for the hydrolysis reaction, 2NO2 + H2O HONO + HNO3 (A) can be quatitatively interpreted by the two step mechanism: 2NO2 → t-ONONO2, t-ONONO2 + H2O → HONO + HNO3. The predicted total forward and reverse rate constants for reaction (A), ktf = 5.36 ×10-50T 3.95exp(1825/T) cm6 molecule-2 s-1 and ktr = 3.31 ×10-19T2.478exp(-3199/T) cm3 molecule-1 s-1, respectively, in the temperature range 200-2500 K, are in good agreement with the available experimental data.
UR - http://www.scopus.com/inward/record.url?scp=84861047374&partnerID=8YFLogxK
U2 - 10.1021/jp302247k
DO - 10.1021/jp302247k
M3 - Article
C2 - 22506560
AN - SCOPUS:84861047374
SN - 1089-5639
VL - 116
SP - 4466
EP - 4472
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 18
ER -