文献类型：期刊文献

英文题名：Study on Pyrolytic Mechanisms of n-Perfluorosilanes SinF2n+2 (2 <= n < 6) and Perfluorocyclosilanes SinF2n (3 <= n <= 6)

作者：Zhao, Yuhan Tang, Anjiang Huan, Qishan Tang, Shiyun Wei, Deju Guo, Junjiang Chen, Lijun

第一作者：Zhao, Yuhan

通信作者：Tang, AJ[1]

机构：[1]Guizhou Inst Technol, Sch Chem Engn, Guiyang 550003, Peoples R China;[2]Guizhou Univ, Sch Chem & Chem Engn, Guiyang 550025, Peoples R China

第一机构：贵州理工学院化学工程学院

通信机构：corresponding author), Guizhou Inst Technol, Sch Chem Engn, Guiyang 550003, Peoples R China.|贵州理工学院化学工程学院;贵州理工学院;

年份：2021

卷号：6

期号：48

起止页码：32841-32851

外文期刊名：ACS OMEGA

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000749695800044)】；

基金：This work was supported by the National Natural Science Foundation of China (no. 21766005), the Science and Technology Planning Project of Guizhou Province (no. Qian Ke He Ping Tai Ren Cai [2019] 5609 and Qian Ke He Zhi Cheng [2021] Yi Ban 493) and the GIT Academic Seedling Training and Innovation Exploration Project (no. GZLGXM11).

语种：英文

摘要：In this paper, the pyrolytic mechanisms of n-perfluorosilanes SinF2n+2 (2 <=<= n < 6) and perfluorocyclosilanes SinF2n (3 <= n <= 6) are studied in terms of kinetics and thermodynamics by theoretical calculation, and the pyrolytic reaction paths of SinF2n+2 (2 <= n < 6) and SinF2n (3 <= n <= 6) are obtained, which can be used to guide the experimental preparation research studies and separation operations of SinF2n+2 (2 <= n < 6), SinF2n (3 <= n <= 6), and their intermediate substances. The results of the kinetic analysis show that the pyrolytic mechanisms of SinF2n+2 (2 <= n < 6) are as follows: first, the silicon-silicon bond breaking induces the generation of free radicals; then, in the chain transfer, the related free radicals participate in F-abstraction transfer with the molecules; and finally, the free radicals form the molecules, and the chain terminates. The F-abstraction transfer is the easiest process to initiate in the low-order silicon-fluorine substance during the chain transfer while releasing SiF2 at the same time, whereas the generation of double free radicals is the most difficult process. The pyrolytic mechanisms of SinF2n (3 <= n <= 6) are as follows: first, the alpha-Si-Si bond breaking induces the generation of double free radicals; then, the alpha-Si-Si or beta-Si-Si bond breaks continually in the chain transfer; and finally, the double free radicals form the molecules, and the chain terminates. SiF2 is most easily formed by breaking during the chain transfer. In the pyrolytic processes of SinF2n+2 (2 <= n < 6) and SinF2n (3 <= n <= 6), the chain initiation of silicon-silicon bond breaking requires the highest bond breaking energy, which is the control step of the pyrolytic reaction. The results of the thermodynamic analysis show that the pyrolytic reactions of SinF2n+2 (2 <= n < 6) and SinF2n (3 <= n <= 6) are endothermic. When SinF2n+2 (2 <= n < 6) undergoes a pyrolytic reaction and the temperature is higher, the main pyrolytic products are SiF4 and SiF2. When 600 K < T < 1200 K, the main pyrolytic products of Si4F10 are Si3F8 and SiF2, and when 900 K < T < 1400 K, Si5F12 can also convert to Si3F8 and SiF2. The main pyrolytic products of SinF2n (3 <= n <= 6) are SiF2. When the temperature is higher, the pyrolytic order of SinF2n (3 <= n <= 6) is as follows: Si3F6 (ring) < Si4F8 (ring) < Si5F10 (ring) < Si6F12 (ring). However, if the temperature is in the range of 1000 K < T < 1200 K, the pyrolytic order is the opposite.