若干三重态硅烯和类硅烯的理论研究

发布时间：2018-06-13 19:15

本文选题：硅烯 + 类硅烯　；参考：《烟台大学》2017年硕士论文

【摘要】：本论文主要研究了若干三重态硅烯和类硅烯的结构、性质和反应。1.采用M06-2X和QCISD方法研究了若干新型含氮杂环卡宾单元的硅烯,计算了它们的单重态及三重态的结构和能量。结果表明,这些硅烯的三重态能量比单重态能量低,基态为三重态,引进氮杂环卡宾骨架能够提高三重态硅烯的稳定性。2.采用M06-2X和QCISD方法研究了若干新型含氮杂环卡宾单元的类硅烯,计算了它们的单重态及三重态的结构和能量。结果表明,这些类硅烯的三重态能量比单重态能量要低,基态为三重态,引进的氮杂环卡宾骨架可以提高三重态类硅烯的稳定性。同时研究了某些三重态类硅烯与NH_3和H_2O的插入反应。3.采用M06-2X和QCISD方法对三重态类硅烯RB=SiLiF(R=CH_3,C_2H_5)在气相中与HF,H_2O和NH_3的插入反应进行了研究。计算结果表明,在插入反应过程中,势能面上存在着一个三元环结构R-Si-H(R=F,OH,NH_2)的过渡态(TS)和一个中间体(IM)连接反应物和产物。RB=SiLiF(R=CH_3,C_2H_5)与RH(R=F,OH,NH_2)发生插入反应的机理相同,但反应活性顺序并不相同,在相同反应条件下反应活性顺序都是H—FH—OHH—NH_2。4.采用M06-2X和QCISD方法对类硅烯H_2SiAlCl_3与RH(R=F,OH,NH_2,Cl,SH,PH_2)在气相和溶剂中的取代反应进行研究。计算结果表明,RH分子可以从两种不同的位置进攻H_2SiAlCl_3分子,从而进一步发生取代反应。而且,当RH分子从Si-Al键的上方进攻时,取代反应更加容易发生。溶剂化效应结果表明,溶剂的存在不利于取代反应的进行。
[Abstract]:In this paper, the structure, properties and reaction of triplet silicene and silylidene are studied. The structure and energy of some new nitrogen-containing heterocyclic carbene units have been studied by M06-2X and QCISD methods. The structure and energy of their singlet and triplet states have been calculated. The results show that the triplet energy of these silicene is lower than that of single state, and the ground state is triplet state. The introduction of carbene skeleton of nitrogen heterocyclic can improve the stability of triplet silicene. By using M06-2X and QCISD methods, the structure and energy of some new nitrogen-containing heterocyclic carbene units are studied. The structure and energy of their singlet and triplet states are calculated. The results show that the triplet energy of these silicene is lower than that of the single state, and the ground state is triplet. The introduction of the carbene skeleton of nitrogen heterocyclic can improve the stability of triplet silicene. At the same time, the insertion reactions of some triplet silicene with NH _ 3 and H _ 2O were studied. M06-2X and QCISD methods were used to study the intercalation reaction of triplet silicene RBSiLiFU RCH3 / C _ 2H _ 5) with HFH _ 2O and NH _ 3 in the gas phase. The calculated results show that during the insertion reaction, there is a transition state (TSTS) and an intermediate (IMM) of a ternary ring structure R-Si-Hn / RFN / NH _ (2) on the potential energy surface. The mechanism of the insertion reaction is the same as that of the RHRRFU / OHH _ (2) / RHRRRFU / OFO _ (NH _ 2) / RHRRRFU / OFO _ (NH _ 2) / RHRRRFU / OFU / NH _ 2) during the intercalation reaction. But the order of reaction activity is not the same. Under the same reaction conditions, the order of reaction activity is H-FH-OHH-NH2.4. M06-2X and QCISD methods were used to study the substitution reactions of 2SiAlCl _ 3 and RHH ~ (+) / R ~ (H ~ (+) ~ (FU) ~ (NH _ (2) / H _ (H _ (H) ~ (NH _ (2) / H _ (H) ~ (2) in the gaseous phase and solvent. The results show that the RH molecule can attack Hs _ 2SiAlCl _ 3 molecule from two different positions, thus the substitution reaction will occur further. Moreover, when RH molecules attack from the top of Si-Al bond, substitution reaction occurs more easily. The solvation effect shows that the existence of solvent is unfavorable to the substitution reaction.
【学位授予单位】：烟台大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O627.41

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