Crossed-beam reaction of carbon atoms with hydrocarbon molecules. III: Chemical dynamics of propynylidyne (l-C3H;X 2Πj) and cyclopropynylidyne (c-C3H;X 2B2) formation from reaction of C(3Pj) with acetylene, C2H2(X 1Σg+)
Crossed-beam reaction of carbon atoms with hydrocarbon molecules. III: Chemical dynamics of propynylidyne (l-C3H;X 2Πj) and cyclopropynylidyne (c-C3H;X 2B2) formation from reaction of C(3Pj) with acetylene, C2H2(X 1Σg+)
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碳原子与烃分子的交叉束反应 III：C(3Pj) 与乙炔 C2H2(X 1Σg+ 反应形成丙炔基 (l-C3H;X 2Πj) 和环丙炔基 (c-C3H;X 2B2) 的化学动力学。 ）
DOI：
10.1063/1.474092
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发表时间：
1997
影响因子：
4.4
通讯作者：
A. Suits
中科院分区：
文献类型：
--
作者：
R. Kaiser;C. Ochsenfeld;M. Head‐Gordon;Y. Lee;A. Suits
基态碳原子C（3 Pj）和乙炔C2 H2（X 1 g+）之间的反应，使用交叉分子束技术在8.8和45.0 kJ mol−1之间的三个碰撞能量下进行了研究。在m/e=37的产物角分布和飞行时间光谱的记录。对数据进行前向卷积拟合得到了弱极化质心角通量分布，当碰撞能量从8.8 kJ mol−1增加到28.0 kJ mol− 1时，相对于碳束的前向散射逐渐减小，在45.0 kJ mol−1时各向同性。从实验数据和从头计算推断的三重态C3 H2和二重态C3 H势能面上的反应动力学表明，通过将C（3 Pj）添加到一个炔碳上形成s-反式丙烯二叉或添加到两个碳原子上通过位于其离心势垒处的松散过渡态产生三重态环丙烯叉而引发两个微通道。丙烯二叉基围绕其B/C轴旋转，并经历[2，3]-H-迁移以形成丙烯二叉基。
The reaction between ground state carbon atoms, C(3Pj), and acetylene, C2H2(X 1Σg+), is studied at three collision energies between 8.8 and 45.0 kJ mol−1 using the crossed molecular beams technique. Product angular distributions and time-of-flight spectra of C3H at m/e=37 are recorded. Forward-convolution fitting of the data yields weakly polarized center-of-mass angular flux distributions decreasingly forward scattered with respect to the carbon beam as the collision energy rises from 8.8 to 28.0 kJ mol−1, and isotropic at 45.0 kJ mol−1. Reaction dynamics inferred from the experimental data and ab initio calculations on the triplet C3H2 and doublet C3H potential energy surface suggest two microchannels initiated by addition of C(3Pj) either to one acetylenic carbon to form s-trans propenediylidene or to two carbon atoms to yield triplet cyclopropenylidene via loose transition states located at their centrifugal barriers. Propenediylidene rotates around its B/C axis and undergoes [2,3]-H-migration to prop...