The decomposition kinetics of disilane and the heat of formation of silylene
The decomposition kinetics of disilane and the heat of formation of silylene
复制标题
乙硅烷的分解动力学和亚硅基的形成热
DOI：
10.1002/kin.550190805
复制
发表时间：
1987
影响因子：
1.5
通讯作者：
H. O'neal
中科院分区：
文献类型：
--
作者：
J. G. Martín;M. A. Ring;H. O'neal
报告了乙硅烷的静态系统分解动力学（538-587 K 和 10-500 Torr）。反应速率常数与压力的关系较弱，数据的最佳拟合是通过使用 logA1,∞ = 15.75 和 E1,∞ = 52,200 cal 的 RRKM 衰减计算来实现的。这些参数产生 AHf0(SiH2)298 = (63.5 − Eb, c) kcal mol,−1 其中 Eb, c 是 550 K 时逆反应的活化能，M = 1 标准状态。其他五个硅烯形成热值（范围从 63.9 – Eb, c 到 66.0 – Eb, c kcal mol−1）是根据报告的丙硅烷和甲基二硅烷的分解动力学以及报告的硅烯插入 H2 和 SiH4 的绝对和相对速率常数推导出来的。假设Eb、c = 0，则得到平均值ΔHf0(SiH2) = 64.3 ± 0.3 kcal mol−1。此外，部分基于新的乙硅烷分解阿伦尼乌斯参数，重新计算亚硅基插入 H2 的活化能，得到 (0.6 + Eb, c) kcal mol−1，与理论计算非常吻合。
The static system decomposition kinetics of disilane (, 538–587 K and 10–500 Torr), are reported. Reaction rate constants are weakly pressure dependent, and best fits of the data are realized with RRKM fall-off calculations using logA1,∞ = 15.75 and E1,∞ = 52,200 cal. These parameters yield AHf0(SiH2)298 = (63.5 − Eb, c) kcal mol,−1 where Eb, c is the activation energy for the back reaction at 550 K, M = 1 std state. Five other silylene heat-of-formation values (ranging from 63.9 – Eb, c to 66.0 - Eb, c kcal mol−1) are deduced from the reported decomposition kinetics of trisilane and methyldisilane, and from the reported absolute and relative rate constants for silylene insertions into H2 and SiH4. Assuming Eb, c = 0, an average value of ΔHf0(SiH2) = 64.3 ± 0.3 kcal mol−1 is obtained. Also, a recalculation of the activation energy for silylene insertion into H2, based in part on the new disilane decomposition Arrhenius parameters, gives (0.6 + Eb, c) kcal mol−1, in good agreement with theoretical calculations.