An experimental and theoretical study of the reactions NaO + H2O(D2O) → NaOH(D) + OH(OD)
An experimental and theoretical study of the reactions NaO + H2O(D2O) → NaOH(D) + OH(OD)
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NaO + H2O(D2O) → NaOH(D) + OH(OD) 反应的实验和理论研究
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发表时间：
1999
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通讯作者：
J. Plane
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作者：
R. M. Cox;J. Plane
用脉冲激光光解Na蒸气、H_2O（D_2O）和N_2O的混合物研究了上述反应。NaO，形成从Na和N2 O之间的反应，通过时间分辨化学发光监测在589 nm（Na（32 PJ-32 S1/2）），从原子O和NaO之间的反应产生。得到k（NaO+H2O，T=260-716 K）=（4.4-1.6+2.4）×10-10 exp（-（507±178）/T）和k（NaO+D2O，T=257-725 K）=（4.2-1.4+2.1）×10-10 exp（-（606±153）/T）cm 3 molecule-1 s-1。然后使用Petersson及其同事的完整基组（CBS-Q）模型（J. Chem. Phys.，1996，104，2598）。这些计算表明：反应基本上是热中性的，Δ H 0 °（NaO+H2O→NaOH+OH）=0.0±7.5 kJ mol-1;小的动力学同位素效应很可能是由于氘代反应比氘代反应多吸热约2 kJ mol-1; 2A″和2A′表面都含有Na（OH）2加合物，其最强结合比反应物低88.2 kJ mol-1（包括零点能）。然后开发了结合Pilling及其同事（J. Phys. Chem. A，1997，101，9681）的逆拉普拉斯变换方法的RRKM模型来研究这些加合物对动力学的影响。最后，这些反应中的钠在中间层的化学作用，并在燃烧系统中的N2 O的去除，被简要地考虑。
The title reactions were studied by the pulsed laser photolysis of a mixture of Na vapour, H2O (D2O) and N2O. NaO, formed from the reaction between Na and N2O, was monitored by time-resolved chemiluminescence at 589 nm (Na(32PJ–32S1/2)), generated from the reaction between atomic O and NaO. This yielded k(NaO+H2O, T=260–716 K)=(4.4-1.6+2.4)×10-10 exp(-(507±178)/T) and k(NaO+D2O, T=257–725 K)=(4.2-1.4+2.1)×10-10 exp(-(606±153)/T) cm3 molecule-1 s-1. Abinitio quantum calculations on the reaction potential energy surfaces were then performed using the complete basis set (CBS-Q) model of Petersson and co-workers (J. Chem. Phys., 1996, 104, 2598). These calculations show that: the reaction is essentially thermoneutral, ΔH0°(NaO+H2O→NaOH+OH)=0.0±7.5 kJ mol-1; the small kinetic isotope effect most likely arises from the deuterated reaction being about 2 kJ mol-1 more endothermic; and both the 2A″ and 2A′ surfaces contain Na(OH)2 adducts, the most strongly bound of which is 88.2 kJ mol-1 below the reactants (including zero-point energies). An RRKM model incorporating the inverse Laplace transformation method of Pilling and co-workers (J. Phys. Chem. A, 1997, 101, 9681) was then developed to investigate the effect of these adducts on the kinetics. Finally, the role of these reactions in the chemistry of sodium in the mesosphere, and in the removal of N2O in combustion systems, is briefly considered.