Zolot Alexander M, Nesbitt David J
JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, USA.
J Chem Phys. 2008 Nov 14;129(18):184305. doi: 10.1063/1.2998524.
Reactive scattering dynamics of F+H(2)O-->HF+OH have been investigated under single-collision, crossed, supersonic jet conditions at 5.4(1.3) kcalmol, and nascent HF(v,J) rovibrational populations (v<or=2, J<or=17) have been observed via high resolution IR laser absorption methods. Vibrational populations are highly inverted, with 75(2)% and 21(5)% of the observed HF product formed in v=1 and 0, respectively. Small but finite branching [5(1)%] into the v=2 manifold is observed, which is accessible only via the additional center of mass collision energy in the crossed jets. Despite energy constraints associated with substantial vibrational excitation, the reaction dynamics also lead to rotationally hyperthermal HF, with populations observed up to near the energetic limit for each of the v=0,1,2 vibrational manifolds. The trends in these nascent product rovibrational distributions are interpreted in terms of ab initio predictions of a strongly bent, early-barrier transition state and long-range dipole-dipole interactions in the exit channel.
在5.4(1.3)千卡/摩尔的单碰撞、交叉超声速射流条件下，研究了F+H₂O→HF+OH的反应散射动力学，并通过高分辨率红外激光吸收方法观测了初生HF(v,J)振转布居（v≤2，J≤17）。振动布居高度反转，观测到的HF产物分别有75(2)%和21(5)%形成于v = 1和v = 0态。观测到有小但有限的分支（5(1)%）进入v = 2态，这仅通过交叉射流中额外的质心碰撞能量才能实现。尽管存在与大量振动激发相关的能量限制，但反应动力学也导致了转动超热的HF，在v = 0、1、2每个振动态的布居观测到接近能量极限。这些初生产物振转分布的趋势根据对强弯曲、早势垒过渡态的从头算预测以及出射通道中的长程偶极 - 偶极相互作用来解释。
