...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Theoretical Investigation of the Kinetics for the Reactions of H with GeH_(4-n)F_n (n = 0, 1, 2, 3)
【24h】

Theoretical Investigation of the Kinetics for the Reactions of H with GeH_(4-n)F_n (n = 0, 1, 2, 3)

机译：H与GeH_（4-n）F_n（n = 0、1、2、3）反应动力学的理论研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The direct hydrogen abstraction reactions of H atoms with GeH_4, GeH_3F, GeH_2F_2, and GeHF_3 have been studied systematically using ab initio molecular orbital theory. For all of the reactions, the potential energy surface information has been calculated at the MP2 level with the 6-311G(2d,p) basis set. Energies along the minimum energy path have been improved by a series of single-point ab initio G2MP2/MP2 calculations. Theoretical analysis provides conclusive evidence that the main process occurring in each case is the hydrogen abstraction from the Ge-H bond; the fluorine abstraction from the Ge-F bond has a higher barrier and is difficult to react. Changes of geometries, generalized normal-mode vibrational frequencies, and potential energies along the reaction path of the reactions are discussed and compared. The reaction thermal rate constants for the temperature range 200-3000 K are deduced by the canonical variational transition-state theory (CVT) with small-curvature tunneling (SCT) correction method. The calculated results show that the variational effect is small and that in the lower-temperature range the small curvature tunneling effect is important for all of the title reactions. The CVT/SCT rate constants exhibit typical non-Arrhenius behavior. Three-parameter rate-temperature formulas have been fitted as follows: k_1 = 1.82 * 10~(-17)T~(2.16) exp(-282.56/T), k_2 = 3.74 * 10~(-18)T~(2.09) exp(-368.21/T), K_3 = 2.43 * 10~(20)T~(2.29) exp(-412.36/T), and k_4 = 1.38 * 10~(-19)T~(2.25) exp(-536.54/T) for the reactions of H with GeH_4, GeH_3F, GeH_2F_2, and GeHF_3, respectively (in units of cm~3 molecule~(-1) s~(-1)). Studies show that the fluorine substitution has an effect on the strength and reactivity of the Ge-H bond in GeH_(4-n)F_n (n = 1 - 3).
机译：利用从头算分子轨道理论系统地研究了H原子与GeH_4，GeH_3F，GeH_2F_2和GeHF_3的直接氢抽象反应。对于所有反应，已使用6-311G（2d，p）基集在MP2级别上计算了势能表面信息。通过一系列单点从头开始的G2MP2 / MP2计算，改善了沿着最小能量路径的能量。理论分析提供了确凿的证据，表明在每种情况下发生的主要过程是从Ge-H键中提取氢。从Ge-F键中提取氟具有更高的势垒并且难以反应。讨论并比较了沿着反应的反应路径的几何形状，广义法模振动频率和势能的变化。通过典型的变分过渡态理论（CVT）和小曲率隧穿（SCT）校正方法推导了200-3000 K温度范围内的反应热速率常数。计算结果表明，变异效应很小，并且在较低温度范围内，小的曲率隧穿效应对于所有标题反应都很重要。 CVT / SCT速率常数表现出典型的非阿累尼乌斯行为。三参数速率-温度公式的拟合如下：k_1 = 1.82 * 10〜（-17）T〜（2.16）exp（-282.56 / T），k_2 = 3.74 * 10〜（-18）T〜（2.09） ）exp（-368.21 / T），K_3 = 2.43 * 10〜（20）T〜（2.29）exp（-412.36 / T），k_4 = 1.38 * 10〜（-19）T〜（2.25）exp（- H分别与GeH_4，GeH_3F，GeH_2F_2和GeHF_3的反应（536.54 / T）（以cm〜3分子〜（-1）s〜（-1）为单位）。研究表明，氟取代对GeH_（4-n）F_n（n = 1-3）中Ge-H键的强度和反应性有影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号