National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan.
J Chem Phys. 2013 Aug 14;139(6):064311. doi: 10.1063/1.4817780.
Two product channels C3H2F + H and C3H3 + F were identified in the reaction of C((3)P) atoms with vinyl fluoride (C2H3F) at collision energy 3.7 kcal mol(-1) in a crossed molecular-beam apparatus using selective photoionization. Time-of-flight (TOF) spectra of products C3H2F and C3H3 were measured at 12-16 laboratory angles as well as a TOF spectrum of atomic F, a counter part of C3H3, was recorded at single laboratory angle. From the best simulation of product TOF spectra, translational-energy distributions at seven scattering angles and a nearly isotropic (forward and backward peaked) angular distribution were derivable for exit channel C3H2F + H (C3H3 + F) that has average kinetic-energy release of 14.5 (4.9) kcal mol(-1). Products C3H2F + H and C3H3 + F were estimated to have a branching ratio of ~53:47. Furthermore, TOF spectra and photoionization spectra of products C3H2F and C3H3 were measured at laboratory angle 62° with photoionization energy ranging from 7 eV to 11.6 eV. The appearance of TOF spectra is insensitive to photon energy, implying that only single species overwhelmingly contributes to products C3H2F and C3H3. HCCCHF (H2CCCH) was identified as the dominant species based on the measured ionization threshold of 8.3 ± 0.2 (8.6 ± 0.2) eV and the maximal translational-energy release. The C/H and C/F exchange mechanisms are stated.
在交叉分子束装置中，使用选择性光解，在 3.7 kcal mol(-1) 的碰撞能下，研究了 C((3)P)原子与乙烯基氟（C2H3F）的反应，确定了两个产物通道 C3H2F + H 和 C3H3 + F。在 12-16 个实验室角度测量了产物 C3H2F 和 C3H3 的飞行时间（TOF）谱，以及产物 C3H3 的原子 F（C3H2F 的对应物）的单实验室角度 TOF 谱。从产物 TOF 谱的最佳模拟中，可以推导出出口通道 C3H2F + H（C3H3 + F）的七个散射角的平移能分布和近乎各向同性（向前和向后峰值）的角分布，该通道的平均动能释放为 14.5（4.9）kcal mol(-1)。产物 C3H2F + H 和 C3H3 + F 的分支比估计约为 53:47。此外，在实验室角度 62°下，用从 7 eV 到 11.6 eV 的光解能测量了产物 C3H2F 和 C3H3 的 TOF 谱和光解谱。TOF 谱的出现对光子能量不敏感，这意味着只有单一物种对产物 C3H2F 和 C3H3 有很大的贡献。根据测量的 8.3 ± 0.2（8.6 ± 0.2）eV 的光解阈值和最大平移能释放，确定 HCCCHF（H2CCCH）为主要物种。陈述了 C/H 和 C/F 交换机制。
