本文選題：分子間弱相互作用　切入點(diǎn)：C-H伸縮振動(dòng)　出處：《浙江理工大學(xué)》2017年碩士論文

【摘要】：分子間弱相互作用在生命科學(xué)及催化領(lǐng)域起著重要的作用,因此近年來被廣泛的研究。對(duì)于調(diào)查研究溶質(zhì)結(jié)構(gòu)和溶液環(huán)境的變化振動(dòng)光譜是種靈敏的工具。通過它可以觀測(cè)振動(dòng)峰的頻率和結(jié)構(gòu)的變化。非重合效應(yīng)(NCE)是與分子間相互作用有關(guān)的重要光譜現(xiàn)象。本論文運(yùn)用顯微拉曼光譜包括基質(zhì)隔離顯微拉曼光譜結(jié)合密度泛函理論(DFT)對(duì)幾種分子的非重合效應(yīng)進(jìn)行了研究。通過對(duì)氘代丙酮的C=O伸縮振動(dòng)模、四氫呋喃的C-H伸縮振動(dòng)模和苯乙酮的C=O伸縮振動(dòng)模的濃度效應(yīng)、非重合(NCE)效應(yīng)和溶劑效應(yīng)的研究,我們對(duì)這些體系中存在的分子間弱相互作用以及分子的聚集結(jié)構(gòu)有新的認(rèn)識(shí)。(1)在文中分別深入的研究了四氫呋喃分子在水溶液及四氯化碳溶液中的C-H伸縮振動(dòng)模的NCE效應(yīng)及濃度效應(yīng)。我們分別采集了THF在水和四氯化碳中從10%到100%濃度的C-H伸縮振動(dòng)模的各項(xiàng)同性拉曼峰和各向異性拉曼峰。在水溶液中,隨著四氫呋喃濃度的增加,我們發(fā)現(xiàn)C-H振動(dòng)模的頻率發(fā)生紅移,NCE效應(yīng)的值相應(yīng)地隨之增加。然而在四氯化碳溶液中四氫呋喃分子的C-H伸縮振動(dòng)模在所有濃度下頻率保持不變,各項(xiàng)同性與各向異性拉曼峰重合,沒有NCE效應(yīng)。同時(shí),我們用MP2計(jì)算四氫呋喃分子的單體及二聚結(jié)構(gòu)來解釋以上的振動(dòng)光譜行為。理論計(jì)算可以很好的與實(shí)驗(yàn)現(xiàn)象相結(jié)合。簡而言之,四氫呋喃在水溶液中的強(qiáng)的分子間的相互耦合作用可以很好的解釋NCE效應(yīng),然而四氫呋喃在四氯化碳溶液中弱的分子間相互耦合作用沒有表現(xiàn)出NCE效應(yīng)。(2)獲取了苯乙酮在四氯化碳溶液中不同濃度時(shí)的拉曼光譜。對(duì)于苯乙酮分子我們發(fā)現(xiàn)隨著苯乙酮-四氯化碳溶液的稀釋,各向同性和各向異性的C=O伸縮振動(dòng)模的頻率發(fā)生藍(lán)移,而NCE值隨之減小。同時(shí)在B3LYP/6-311++G(d,p)計(jì)算水平上優(yōu)化苯乙酮的單體和二聚結(jié)構(gòu),計(jì)算結(jié)果可以很好地與實(shí)驗(yàn)結(jié)果相吻合。(3)為了詳細(xì)的了解氘代丙酮在四氯化碳中C=O伸縮振動(dòng)模的NCE效應(yīng),我們獲取了體積分?jǐn)?shù)從30%到100%的氘代丙酮顯微拉曼光譜以及它的偏振顯微拉曼光譜。隨著濃度的增加C=O峰頻率發(fā)生紅移。隨著溶液的稀釋,NCE的值隨著減小。同時(shí)收集了低溫氬氣基質(zhì)隔離中的氘代丙酮的顯微拉曼光譜,觀察到在8 K時(shí)氘代丙酮C=O伸縮譜帶是一個(gè)尖銳的單峰,25K時(shí)分裂成兩個(gè)小峰。同時(shí)我們利用Gaussian09在MP2/6-311++G(d,p)計(jì)算水平上優(yōu)化氘代丙酮單體和二聚結(jié)構(gòu),計(jì)算表明氘代丙酮分子通過分子間相互作用分別可以形成頭對(duì)尾平行的二聚結(jié)構(gòu),這種二聚結(jié)構(gòu)可以很好地解釋氘代丙酮C=O振動(dòng)模的NCE效應(yīng)。
[Abstract]:Weak intermolecular interaction plays an important role in life sciences and catalysis, so it has been widely studied in recent years.It is a sensitive tool for investigating the variation of solute structure and solution environment.The frequency and structure of the vibration peak can be observed by it.Noncoincidence effect (NCE) is an important spectral phenomenon related to intermolecular interaction.In this paper, the noncoincidence effects of several molecules have been studied by means of micro-Raman spectroscopy, including matrix isolated micro-Raman spectroscopy and density functional theory (DFT).The concentration effect, noncoincidence NCE-effect and solvent effect of C-H stretching vibration modes of deuterated acetone, C-H stretching vibration modes of tetrahydrofuran and acetophenone are studied.We have a new understanding of the weak intermolecular interaction and the molecular aggregation structure in these systems. (1) the C-H stretching vibration modes of tetrahydrofuran molecules in aqueous solution and carbon tetrachloride solution have been studied in this paper.NCE effect and concentration effect.We have collected the isotropic and anisotropic Raman peaks of C-H stretching vibrational modes of THF in water and carbon tetrachloride from 10% to 100% respectively.With the increase of tetrahydrofuran concentration in aqueous solution, we find that the frequency of C-H vibrational mode increases with the red shift NCE effect.However, in the solution of carbon tetrachloride, the C-H stretching vibrational modes of tetrahydrofuran remain constant at all concentrations, and the isotropic and anisotropic Raman peaks coincide with each other, and there is no NCE effect.At the same time, we use MP2 to calculate the monomer and dimer structure of tetrahydrofuran molecule to explain the above vibrational spectrum behavior.Theoretical calculation can be well combined with experimental phenomena.In short, the strong intermolecular coupling of tetrahydrofuran in aqueous solution can explain the NCE effect well.However, the weak intermolecular coupling of tetrahydrofuran in carbon tetrachloride solution does not show the NCE effect.) Raman spectra of acetophenone in different concentrations of acetophenone in carbon tetrachloride solution were obtained.For acetophenone molecules we find that with the dilution of acetone-carbon tetrachloride solution the frequency of isotropic and anisotropic Con O stretching vibrational modes is blue shifted and the NCE value decreases.At the same time, the monomer and dimer structures of acetophenone were optimized at the level of B3LYP/6-311 GDX. The calculated results were in good agreement with the experimental results. (3) in order to understand the NCE effect of deuterated acetone in CCO stretching vibration mode in carbon tetrachloride in detail,The microscopic Raman spectra of deuterated acetone from 30% to 100% in volume fraction and its polarization microRaman spectra were obtained.With the increase of concentration, the frequency of Con O peak shifts red.The value of NCE decreases with the dilution of the solution.The microRaman spectra of deuterated acetone isolated in low temperature argon substrate were also collected. It was observed that the C-O stretching band of deuterated acetone at 8 K was a sharp single peak and split into two small peaks at 25 K.At the same time, we optimize the deuteriated acetone monomer and dimer structure at the level of MP2/6-311 MP2/6-311 by using Gaussian09. The results show that the deuteriated acetone molecules can form a head to tail parallel dimer structure by intermolecular interaction.The dimeric structure can explain the NCE effect of the vibrational mode of deuterated acetone.
【學(xué)位授予單位】：浙江理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O657.37

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本文編號(hào)：1729412