若干tetrel bond复合物的结构和性质的理论研究

发布时间：2018-03-11 07:32

  本文选题：Tetrel　切入点：bond　出处：《烟台大学》2017年硕士论文　论文类型：学位论文

【摘要】：本论文主要研究了一种新型分子间相互作用-tetrel bond,其在晶体材料、化学反应以及生物等领域有重要应用。本论文利用理论化学计算方法研究了几个重要体系中tetrel bond的形成、本质、作用规律、应用及其强度调控。主要研究成果如下:卡宾和假卤离子N_3-/OCN-/SCN-可以作为Lewis碱参与形成tetrel bond,提出了卡宾tetrel bond和假卤离子tetrel bond。这些复合物的稳定性取决于tetrel原子与Lewis碱的性质。在TH_3F…NHC复合物中,tetrel bond 按 T=CGeSnSi顺序增强。这些tetrel bonds主要由静电作用主导,同时轨道作用也起重要贡献。强tetrel bond作用还归因于从Lewis碱的孤对电子到T-Y和T-H反键轨道的电子转移,并且前一种轨道作用使得T-F键伸长和相应伸缩振动发生红移。取代基和杂化可以调节tetrel bond的强度。Tetrel给体中的吸电子基团增强tetrel b ond,而受体中的吸电子基团减弱tetrel b ond。Lewi s碱中的给电子基团增强tetrel bond,其主要是通过静电和极化作用引起的。Tetrel bond按照p-PySiF_3…NCH(sp)p-PySiF_3…NHCH_2(sp2)p-PySiF_3…NH_3(sp3)顺序增强。Tetrel bond可以与其它类型作用存在协同作用。在H_2C…CH_3CN…M(M = CH_3CN,HCN,ICN,SbH_2F,LiCN,BeH_2)三元体系中,卡宾tetrel bond通过协同效应增强,且在H_2C…CH_3CN…BeH_2中其作用能增加了两倍。研究了 PySiX3与一系列氮碱形成的tetrel bond 和 PySiX3与 BF_3、BCl3 及 SO3 形成的 triel/chalcogen bond 之间的协同作用。发现三聚体中tetrel bond与triel/chalcogen bond存在协同效应,这种协同作用主要是由极化作用引起的。研究了 BeH_2…XTH_3…NH_3(X = F,Cl,Br;T = C,Si,Ge)复合物中tetrel bond与铍键之间的协同作用。发现铍键与tetrel bond相互增强,且tetrel bond增强的程度比铍键的更明显,这主要归结于相关原子的静电势增加和电荷转移增多。质子化对tetrel bond 有显著的影响。质子化使得α/β-furanCF_3/p-PyCF_3和NH_3之间的作用类型从F…H氢键变为C…N tetrel bond。质子化使得tetrel bond强度显著增加,作用能从-14.15 kcal/mol 增加到-30.09 kcal/mol。Tetrel bond 按照 H+-p-PySiF_3…NH_3H+-m-PySiF_3…NH_3H+-o-PySiF_3…NH_3顺序增强,与中性复合物中的变化相反。Tetrel bond在S_N2反应中扮演重要角色。N_3-形成的tetrel bond在N_3-+ CH_3Br→Br-+ CH_3N_3反应中起前驱体作用,而在F-+ CH_3N_3 → N_3-+ CH_3F反应中起后驱体作用。
[Abstract]:In this paper, a new type of intermolecular interaction-tetrel bond, which has important applications in crystal material, chemical reaction and biology, has been studied. The formation and nature of tetrel bond in several important systems have been studied by theoretical chemical calculation method. The law of action, The main research results are as follows: carbene and pseudohalide N3 / OCN-r SCN- can participate as Lewis base to form tetrel bond. It is proposed that carbene tetrel bond and pseudohalide tetrel bond.The stability of these complexes depends on tetrel atom and Lewis base. In the TH_3F... NHC complex, the tetrel bond is enhanced in TGe Sn-Si order. These tetrel bonds are dominated by electrostatic action. The strong tetrel bond interaction is also attributed to the electron transfer from solitary pair electrons of Lewis base to T-Y and T-H antibonding orbitals. Moreover, the former orbital action results in red-shift of T-F bond elongation and corresponding stretching vibration. The substituents and hybrids can adjust the intensity of tetrel bond. The electron-absorbing groups in the tetrel bond donor enhance tetrel bond, while the acceptor groups weaken tetrel. The electron donor group in the b ond.Lewi s base enhances the tetrel bond, which is mainly caused by electrostatic and polarization actions. Tetrel bond enhances the order of p PySiF3... NCH(sp)p-PySiF_3... NHCH_2(sp2)p-PySiF_3... NH3 sp3). Tetrel bond can have synergistic effects with other types of actions. In H2C... CH_3CN... MM. In the C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C / C. Carbene tetrel bond is enhanced by synergy, The synergistic effect between PySiX3 and tetrel bond formed by a series of nitrogen bases and PySiX3 with triel/chalcogen bond formed by BF3C BCl 3 and SO3 was studied. It was found that there was a synergistic effect between tetrel bond and triel/chalcogen bond in trimer. The synergism between tetrel bond and beryllium bond in BeH_2... XTH_3... NH_3(X = NH_3(X = CnSiGe complex is mainly caused by polarization. It is found that beryllium bond and tetrel bond reinforce each other, and tetrel bond enhancement is more obvious than that of beryllium bond. This is mainly attributed to the increase in electrostatic potential and charge transfer of the related atoms. Protonation has a significant effect on tetrel bond. Protonation causes the type of interaction between 伪 / 尾 -furan CFC _ 3 / p-PySP _ 3 and NH_3 from F 鈥，

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