Sieck L W, Lias S G, Hellnery L, Ausloos P
Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234.
J Res Natl Bur Stand A Phys Chem. 1972 Mar-Apr;76A(2):115-124. doi: 10.6028/jres.076A.012.
1-Butene, -2-butene, isobutene and methylcyclopropane have been photoionized with the resonance lines of krypton (10.0-10.6 eV) and argon (11.6-11.8 eV). We have determined that the internally excited ion and, to a much lesser extent, the ion isomerizes to the structure. In both cases the extent of isomerization increases, approximately by a factor of ten when the photon energy is increased from 10 to 11.7 eV. An inert gas, neon, quenches the isomerization of the ion and, to a much lesser rextent, that of the ion. The unimolecular fragmentation of the isomeric ions has been examined at 11.61-11.8 eV. In this energy range the dissociative lifetime of was found to be at least 5 × 10 s, and collisional quenching of the dissociative process is already noticeable at pressures in the 10 torr range. The rate coefficients for the reaction occurring in the isomeric CH systems have been determined under conditions where the structure of the reacting ion is established. The values in cm/molecule · second are 1-CH - 6.0 ± 0.5 × 10, -2-CH - 0.37 ± 0.1 × 10, -CH - 5.4 ± 0.4 × 10. At pressure below 10 torr, the internally excited produced in the reaction dissociates along various channels with relative probabilities depending upon the structure of both the ionic and neutral reactant. Above 10 torr collisional quenching of is noted.
1-丁烯、-2-丁烯、异丁烯和甲基环丙烷已用氪（10.0 - 10.6电子伏特）和氩（11.6 - 11.8电子伏特）的共振线进行了光电离。我们已确定内部激发的离子，以及在小得多的程度上，离子异构化为结构。在这两种情况下，当光子能量从10电子伏特增加到11.7电子伏特时，异构化程度增加，大约增加了10倍。惰性气体氖会淬灭离子的异构化，以及在小得多的程度上，离子的异构化。已在11.61 - 11.8电子伏特下研究了异构离子的单分子裂解。在这个能量范围内，发现的解离寿命至少为5×10秒，并且在10托范围内的压力下，解离过程的碰撞淬灭已经很明显。在确定反应离子结构的条件下，已测定了异构CH系统中发生的反应的速率系数。单位为厘米/分子·秒的值为1-CH - 6.0±0.5×10，-2-CH - 0.37±0.1×10，-CH - 5.4±0.4×10。在低于10托的压力下，反应中产生的内部激发离子会沿着各种通道解离，相对概率取决于离子和中性反应物的结构。在高于10托时，会注意到的碰撞淬灭。
