稀土谷胱甘肽配合物红外和Raman光谱研究

谷胱片肽是广泛存在于体内的重要三肽, 在体内主要以还原型(GSH)存在. GSH不但是清除体内过氧化物的还原剂, 而且与某些金属的配合物具有酶活性. 随着稀土的广泛应用, 其生物效应已引起关注. 了解稀土与GSH的配合物结构和性质, 将有利于了解稀土在体内的代谢和作用. 本文合成了十五种稀土与GSH的固体配合物,用IR和Raman光谱研究了配体在配合物中的变化及与稀土的配合位置.     

2,2,2-三氯乙基·甲基醚的红外和Raman光谱及其振动归属

本文给出了2,2,2-三氯乙基·甲基醚的红外(3500-40cm^-1)和Raman(3500-50'^-1)光谱以及液相Raman谱退偏比的首次实验数据。利用修正价力场的正则坐标计算完成了两种构型的正则模式和势能分布的计算,从而做出频率的振动归属。由红外谱线606(反式)和573cm^-1(旁式)相对强随温度变化的关系求出平均热函差为161±11cm^-1(1922±134J/mol),证明两种构型中反式较旁式稳定。     

新戊二醇-三羟甲基甲胺二元体系相图

多元醇是一类具有技术和经济潜力的相变贮热材料［１ -３］．对多元醇及其二元体系贮热性能的研究已日趋完善,而对于其相图的研究则较少．本文采用以下三种实验技术测绘了ＮＰＧ ＴＡＭ二元体系相图：（１）热分析,以得到组成与相转变温度的关系;（２）变温红外光谱的研究,通过特征吸收峰随温度的变化,可以得到相转变温度区间,辅助相图的绘制;（３）Ｘ射线衍射,通过淬冷的方法来获得高温下的物相,测其Ｘ衍射图,进行相区分析．１实验１．１试剂ＮＰＧ：为超纯试剂,日本东京化成株式工业会社生产：ＴＡＭ：分析纯,北京化学试剂厂…     

青蒿素的Raman光谱研究

本文对固态青蒿素的FT-Raman光谱和普通Raman光谱以及低浓度(1×10^-^5mol/L)青蒿素水溶液的表面增强Raman散射(SERS)光谱进行了检测, 着重观察了1756cm^-^1六元内酯环振动谱带, 发现其在FT-Raman和普通Raman光谱中表现为强振动, 而在SERS光谱中此振动谱带消失, 说明分子内酯环发生了破裂。根据1756cm^-^1谱带的变化以及724cm^-^1过氧基团振动频率的位移, 对青蒿素在银表面上的吸附取向进行了研究。还研究了青蒿素与氯高铁血红素的作用情况, 发现两者作用后, 明显改变了青蒿素在银表面上的吸附。     

煤基石墨的Raman光谱研究

对我国湖南省鲁塘地区煤基石墨系列样品的Raman光谱分析和研究表明,所有煤基石墨的一级Raman光谱都存在石墨固有的层内振动谱峰E_(2g),其频移位于1585cm~(-1)附近;层内振动的缺陷谱峰,即D峰有二种,一是由原生结构缺陷引起的D_2峰,其频移位于1360cm~(-1),另一是由次生结构缺陷引起的D_1峰,其频移位于1370cm~(-1);煤基石墨的二级Raman光谱反映它的三维晶格完善程度。     

凝胶纳米氧化钛Raman光谱研究

纳米材料近来成为材料科学的研究热点[1]．催化剂实际上大多是纳米材料．TiO2有多方面的用途，比如它是重要的新型催化剂载体，其纳米微粒，由于比表面高，将有利于改善其催化性能[2]．Raman光谱是研究纳米微粒的新手段，现已发现随着拉径减小到纳米县级，原有Raman峰将产生低频位移和宽化，还可能出现新峰．另外，低频Raman谱段还可能出现散射峰，这些现象均可提供宝贵的纳米结构信息[7,8]．文献中对锐钛矿型TiO2纳米粒子的研究较少[4],而未见对其进行低频Raman测量的报道.本文对用sol-gel方法经不同制备条件合成的一系列锐钛矿型纳米T…     

γ-甲基吡啶电氧化过程的表面增强Raman光谱研究

本文在光纤采样系统的基础上设计了一套双工作电极电解池, 将工作电极与检测电极分开, 并借助SERS高灵敏特点实现了电解过程的现场Raman光谱跟踪。PbO2电极上γ-甲基吡啶的电氧化产物为γ-甲酸吡啶, 在实际硫酸介质中, 产物以质子化的离子对存在。     

金刚石Raman光谱荧光本底及其对高压原位Raman光谱测试的影响

金刚石对顶砧(diamond anvil cell,DAC)装置(如图1所示)是目前产生压力最高的静态高压实验装置,它以金刚石单晶作对顶砧单轴挤压样品产生高压,由于金刚石在很宽的能量范围对光子(可见光、高能X射线等)透明,在高压实验中可以通过显微镜观察样品,并可对样品进行高压原位X射线衍射和光谱(红外光谱、Raman光谱等)测试,这一特点使其在高压科学领域得到广泛的应用.在高压原位Raman光谱测试中,激发光源透过金刚石对顶砧照射到样品上产生Raman信号,样品的Raman信号穿过金刚石对顶砧经显微镜物镜收集并最终被探测器接收.与常规的Raman光谱测试相比,基于DAC装置的高压原位Raman光谱测试光路中多出了金刚石对顶砧,需要采用长焦物镜收集信号,并且随着实验压力的升高,样品的Raman信号强度降低,因此提高信噪比是获得较高质量高压原位Raman光谱的关键,而金刚石对顶砧的荧光本底是影响信噪比的关键因素.本文通过对20多颗金刚石对顶砧进行Raman光谱测试,对金刚石的Raman光谱信号(一级和二级)和非随机噪声进行了系统的评估,并结合高压原位Raman光谱测试的具体特点,探讨金刚石对顶砧荧光本底对测试结果的影响.     

Raman and Infrared Spectra, Ab Initio Calculations, Normal Coordinate Analysis, and Conformational Stability of 2-Methoxypropene

The Raman (3500–40 cm^–1) and infrared (3500–70 cm^–1) spectra of gaseous and solid 2-methoxypropene, CH₃O(CH₃)C=CH₂, and the isotopomers, CD₃O(CH₃)C=CH₂ and CH₃O(CD₃)C=CD₂ have been recorded. In addition, the Raman spectra of the liquids have been recorded with qualitative depolarization measurements. All of these data indicate that only one conformer is present in the fluid phases at ambient temperature and this form is the cis conformer, which remains in the solid. Assignments are provided for the fundamentals of all three isotopomers for the cis conformer with C_s symmetry. The far-infrared spectra of all three isotopic species have been recorded at a resolution of 0.1 cm^–1 in the gas and 1.0 cm^–1 in the solid. The parameters of the potential function governing the asymmetric torsion are determined to be V₃ = 1485 ± 9 cm^–1 and V₆ = –55 ± 4 cm^–1 for the d₀ compound, where only two terms were determined, since a second conformer was not evident. The barrier to internal rotation for the methyl group attached to the oxygen atom is 1370 ± 8 cm^–1 and the C—CH₃ barrier is 772 ± 5 cm^–1. Ab initio calculations with full electron correlation have been carried out by the perturbation method to second order to obtain the equilibrium structural parameters, harmonic force constants, fundamental frequencies, infrared intensities, Raman activities, depolarization values, and conformational stability. The predicted values have been compared to the experimental values where appropriate.     

Si2Br6的分子振动光谱的理论研究

用量化从头算方法(HF/6-31G^*)和密度泛函方法(B3LYP/6-31G^*)以6-31G标准基组加一个极化函数,对Si₂Br₆分子的平衡几何构型和振动频率分别进行优化和计算,优化的结果与实验结果吻合得较好.按照Pulay的建议对HF/6-31G^*水平上所计算的谐性力场进行标度(标度因子取0.9).用HF/6-31G^*SQM力场所计算的基频预测值和实验值的平均误差为9.4cm^-1,最大误差为23.6cm^-1;用B₃LYP/6-31G^*未标度力场所计算的基频预测值和实验值的平均误差为8.6cm^-1,最大误差为16.6cm^-1;用该密度泛函方法所计算的基频预测值比用HF/6-31G^*的标度后的SQM力场所计算的基频预测值和实验值(除Si-Si键扭转振动基频之外的11条振动基频)吻合得更好.HF/6-31G^*和B3LYP/6-31G^*计算给出Si-Si键扭转振动基频的预测值分别为14cm^-1和9cm^-1.     

羧基为核收敛的多醚树枝状大分子的红外与拉曼光谱分析

根据文献合成了第一、第二和第三代羧基为核收敛的多醚树枝状大分子(缩写为G1、G2和G3)。利用振动光谱数据,结合X-衍射结构分析,从G1的结构推想出G2和G3的可能结构。以2,5二甲基苯基醚作为模型分子,把复杂分子拆成组成结构进行光谱分析,从而对产物G1、G2和G3的谱带作了初步归属。     

Metal Complexes of Aniline: Infrared and Raman Spectra

Abstract

The literature for the years 1965–1987 has been searched for all significant papers which refer to the vibrational spectra of metal complexes of aniline and substituted anilines. These papers have been reviewed with particular reference to isotopic labelling and metal ion substitution studies as assignment techniques and to the structural and bonding information which can be derived from the spectra. Compounds of the following classes are included: [M(an)₂X₂] (M = Mn, Co, Ni, Cu, Zn, Cd, Hg; an = aniline, X - Cl, Br, I, NCS); cis- and trans-[Pt(an)₂X₂] (X = Cl, Br, I, NO₂); [M(R-an)₂X₂] (M = Mn, Co, Ni, Cu, Zn; R-an = o-, m- and p-toluidine and other substituted anilines; X = Cl, Br, I); aniline adducts of metal β-ketoenolates; the complexes trans-[PtL(R-an)X₂] (L = CH₂?CH₂ or CO, R-an = aniline or a substtuted aniline, X = Cl, Br); and other miscellaneous systems comprising aniline as a ligand.     

[Cl_3Sb(μ-S)SbCl_3]~(2-)阴离子的红外光谱和简正坐标分析

在500—100cm~(-1)波段范围内测定了[Cl_3Sb(μ-S)SbCl_3]~(2-)阴离子的Fourier变换红外光谱。采用简化的普遍价力场(SGVFF)进行了简正坐标分析,振动基频的计算值与观测值符合良好,两者平均偏差小于1.0％,证实了振动谱带的归属,确定了相应的力常数。最后讨论了谱带归属问题和所得结果的合理性和可靠性。     

Raman and Infrared Spectra for All-trans-astaxanthin in Dimethyl Sulfoxide Solvent

The Raman and infrared spectra of all-trans-astaxanthin (AXT) in dimethyl sulfoxide (DMSO) solvent were investigated experimentally and theoretically. Density functional cal-culations of the Raman spectra predict the splitting of the υ₁ band into υ_1-1 and υ_1-2 compo-nents. The absence of splitting in Raman experimental spectra is ascribed to the competition between the two symmetric C=C stretching vibrations of the backbone chain. The υ₁ band is very sensitive to the excitation wavelength: resonance excitation stimulates the higher-frequency υ_1-2 mode, and off-resonance excitation corresponds to the lower-frequency υ_1-1 mode. Analyses of the intramolecular hydrogen bonding between C=O and O-H in the AXT/DMSO system reveal that the C4=O1...H1-O3 and C4'=O2...H2-O4 bonds are strengthened and weakened, respectively, in the electronically excited state compared with those in the ground state. This result reveals significant variations of the AXT molecular structure in different electronic states.     

酰胺型双冠醚的振动光谱分析

对邻苯-二(氧乙酰胺-4'-本并-15-冠-5)、间苯-二(氧乙酰胺-4'-苯并-15-冠-5)、对苯-二(氧乙酰胶-4'-苯并-15-冠-5)三种酰胺型双冠醚和苯并15-冠-5的喇曼光谱及红外光谱进行了测定和归属分析,并与15-冠-5的喇曼及红外光谱进行了比较研究.     

稀土二苯甲酰甲烷螯合物Ln(DBM)3·H2O振动光谱的简正坐标分析

本文报道了Ln(DBM)_3·H_2O的简正坐标分析结果, 计算中采用了单螯合坏近似模型, 计算结果和红外、拉曼光谱观测频率符合较好, 所得到的一组力常数, 具有较好的转移性质. 讨论了一些重要谱带的性质。     

Resonance Raman and Infrared Spectra of Carbene Complexes of Iron Porphyrins Dongsheng Lu

Abstract

The resonance Raman and infrared spectra of four carbene complexes, Fe(TTP)CCl₂, Fe(TPP)¹³CCl₂, Fe(TPP)CBr₂ and Fe(TMP)CCl₂ were measured in the solid state. Based on normal coordinate calculations and observed isotopic shifts by CC1₂/¹³CC1₂ substitution, the v(Fe=C), v_a(CCl₂) and v_s(CCl₂) vibrations were assigned at 1274, 878 and 437cm^?1, respectively. The bromo analogue exhibits these bands at 1270,823 and 364 cm^?1, respectively. All TPP complexes exhibit the spin-state sensitive band (v₂) at 1569 cm^?1 and the oxidation-state sensitive band (v₄) at 1370cm^?1, thus suggesting that the Fe atoms in these carbene complexes are low-spin Fe(IV).     

红外光谱和拉曼光谱法分析玉米种子的成分

采用傅立叶红外光谱法(FTIR)及拉曼光谱分析了玉米种子不同部位的成分。实验表明,不同部位蛋白质、脂类和碳水化合物的特征吸收峰的相对强弱是不同的。玉米种子的胚中这3种物质的特征吸收峰强度较为均匀,差别不大。胚乳中脂类特征吸收峰最强,显示胚乳中脂类占据主导。白色的糊粉层则以碳水化合物为主。而外层黄色部位蛋白质和碳水化合物的吸收峰较强,脂类的吸收峰很小。拉曼光谱分析可以看到玉米种子的类胡萝卜素含量从黄色的外层到胚逐渐降低。