Gas-phase reactions between silane and water: A theoretical study
Gas-phase reactions between silane and water: A theoretical study
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DOI：
10.1021/jp036836g
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发表时间：
2004-02-26
影响因子：
2.9
通讯作者：
Liu, XQ
中科院分区：
文献类型：
--
作者：
Hu, SW;Wang, Y;Liu, XQ
在 CCSD(T)/6-311++G**//MP2/6-31+G* 水平上使用从头计算研究了硅烷 (SiH4) 和水 (H2O) 之间的气相反应。在 160 kcal/mol 的能量范围内，我们在 Si-O-H 体系的势能面上定位了 40 个平衡态和 27 个过渡态。在 46.61 kcal/mol 的能量势垒上，弱键合分子复合物 SiH4-H2O 可以消除第一个 H-2 分子并产生硅烷醇 (SiH3OH)。过渡态是二氢键结构，保留了硅烷构型。直接产物SiH3OH + H-2 相对于反应物的总能量为-10.83 kcal/mol。在 58.09 kcal/mol 的能量势垒上，SiH4-H2O 可以消除第一个 H-2 并产生瞬态配位键复合物 SiH2-H2O。为系统提供更多的能量，SiH4-H2O可以原子解离，初始产物可以进一步消除H-2或H，产生更小的物质，包括分子SiH-OH、SiH2-O、Si-H2O和SiO以及自由基SiH2-OH、SiH-H2O、HSiO和HOSi。
Gas-phase reactions between silane (SiH4) and water (H2O) were investigated using ab initio calculations at the CCSD(T)/6-311++G**//MP2/6-31+G* level. Within the energy range of 160 kcal/mol, we located 40 equilibrium and 27 transition states on the potential energy surfaces of the Si-O-H systems. Over an energy barrier of 46.61 kcal/mol, the weakly bonded molecular complex SiH4-H2O can eliminate first H-2 molecule and produce silanol (SiH3OH). The transition state is a dihydrogen-bonded structure with retention of the silane configuration. The total energy of the direct products SiH3OH + H-2 is -10.83 kcal/mol relative to the reactants. Over an energy barrier of 58.09 kcal/mol, SiH4-H2O can eliminate first H-2 and produce a transient dative bonded complex SiH2-H2O. Providing more energy to the system, SiH4-H2O can dissociate atomically and the initial products can further eliminate H-2 or H, producing smaller species including molecules SiH-OH, SiH2-O, Si-H2O, and SiO and radicals SiH2-OH, SiH-H2O, HSiO, and HOSi.