本文選題：Tetrel　切入點(diǎn)：bond　出處：《煙臺(tái)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：本論文主要研究了一種新型分子間相互作用-tetrel bond,其在晶體材料、化學(xué)反應(yīng)以及生物等領(lǐng)域有重要應(yīng)用。本論文利用理論化學(xué)計(jì)算方法研究了幾個(gè)重要體系中tetrel bond的形成、本質(zhì)、作用規(guī)律、應(yīng)用及其強(qiáng)度調(diào)控。主要研究成果如下:卡賓和假鹵離子N_3-/OCN-/SCN-可以作為L(zhǎng)ewis堿參與形成tetrel bond,提出了卡賓tetrel bond和假鹵離子tetrel bond。這些復(fù)合物的穩(wěn)定性取決于tetrel原子與Lewis堿的性質(zhì)。在TH_3F…NHC復(fù)合物中,tetrel bond 按 T=CGeSnSi順序增強(qiáng)。這些tetrel bonds主要由靜電作用主導(dǎo),同時(shí)軌道作用也起重要貢獻(xiàn)。強(qiáng)tetrel bond作用還歸因于從Lewis堿的孤對(duì)電子到T-Y和T-H反鍵軌道的電子轉(zhuǎn)移,并且前一種軌道作用使得T-F鍵伸長(zhǎng)和相應(yīng)伸縮振動(dòng)發(fā)生紅移。取代基和雜化可以調(diào)節(jié)tetrel bond的強(qiáng)度。Tetrel給體中的吸電子基團(tuán)增強(qiáng)tetrel b ond,而受體中的吸電子基團(tuán)減弱tetrel b ond。Lewi s堿中的給電子基團(tuán)增強(qiáng)tetrel bond,其主要是通過靜電和極化作用引起的。Tetrel bond按照p-PySiF_3…NCH(sp)p-PySiF_3…NHCH_2(sp2)p-PySiF_3…NH_3(sp3)順序增強(qiáng)。Tetrel bond可以與其它類型作用存在協(xié)同作用。在H_2C…CH_3CN…M(M = CH_3CN,HCN,ICN,SbH_2F,LiCN,BeH_2)三元體系中,卡賓tetrel bond通過協(xié)同效應(yīng)增強(qiáng),且在H_2C…CH_3CN…BeH_2中其作用能增加了兩倍。研究了 PySiX3與一系列氮堿形成的tetrel bond 和 PySiX3與 BF_3、BCl3 及 SO3 形成的 triel/chalcogen bond 之間的協(xié)同作用。發(fā)現(xiàn)三聚體中tetrel bond與triel/chalcogen bond存在協(xié)同效應(yīng),這種協(xié)同作用主要是由極化作用引起的。研究了 BeH_2…XTH_3…NH_3(X = F,Cl,Br;T = C,Si,Ge)復(fù)合物中tetrel bond與鈹鍵之間的協(xié)同作用。發(fā)現(xiàn)鈹鍵與tetrel bond相互增強(qiáng),且tetrel bond增強(qiáng)的程度比鈹鍵的更明顯,這主要?dú)w結(jié)于相關(guān)原子的靜電勢(shì)增加和電荷轉(zhuǎn)移增多。質(zhì)子化對(duì)tetrel bond 有顯著的影響。質(zhì)子化使得α/β-furanCF_3/p-PyCF_3和NH_3之間的作用類型從F…H氫鍵變?yōu)镃…N tetrel bond。質(zhì)子化使得tetrel bond強(qiáng)度顯著增加,作用能從-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順序增強(qiáng),與中性復(fù)合物中的變化相反。Tetrel bond在S_N2反應(yīng)中扮演重要角色。N_3-形成的tetrel bond在N_3-+ CH_3Br→Br-+ CH_3N_3反應(yīng)中起前驅(qū)體作用,而在F-+ CH_3N_3 → N_3-+ CH_3F反應(yīng)中起后驅(qū)體作用。
[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 偽 / 尾 -furan CFC _ 3 / p-PySP _ 3 and NH_3 from F 鈥，

本文編號(hào)：1597176