首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
用高灵敏的光腔衰荡光谱(Cavity Ring-Down Spectroscopy)方法探测到了正丙醇波长在620和700nm附近的高激发泛频振动光谱,将其归属于分子不同稳定构象的O-H伸缩振动(ν=4、5)泛频吸收,谱带用高斯函数模拟后得到的每一个峰都对应于分子的一个或几个稳定构象。用局域模理论(Local Mode Theory)对同一分子的不同泛频振动(ν值不同)进行了分析指认,求出了分子羟  相似文献   

2.
利用傅里叶变换拉曼光谱和傅里叶变换红外光谱对H2O/KDEGP(75%)-HDEHP(25%)/n=HEP-TANE微乳体系的表面活性剂疏水链和极性头基与水分子的相互作用进行了研究。结果表明:当加水量由W0=1增加至43时,表面活性有性头基[PO2]^-的反对称伸缩振动由1233cm^-1移至1207cm^-1,其对称伸缩振动由1094cm^-1移至1089cm^-1。表面活性剂疏水链的堆结构也发  相似文献   

3.
以3种广泛使用的描述分子局域模振动的理论模型讨论了球陀螺分子的伸缩振动泛频态的振动角动量及科里利相互作用。3种模型在计算极端局域振动模态(n000)的科里奥利系数有效值时,给出定性一致的结果。但是,对于(2100)合频态,只有HCAO I模型给出与实验结果相近的计算结果,HCAOⅡ和NMDD模型的计算结果都有较大的偏差。从波函数形式、基矢态的性质等方面分析了HCAOⅠ和Ⅱ模型的计算结果差异的原因,  相似文献   

4.
我们合成有机锗化合物的理要中间体4-三氯锗基-4-甲基-2-戊酮(A)、3-三氯锗基-3,5,5-三甲基环已酮(B)、2-三氯锗基-2-苯基乙基苯基酮(C)、2-三苯基锗基乙基苯基酮(D),没测量了他们的Ramam和IR光谱半进行了讨论。在化合物A-D的Ramam和IR光谱,苯环中的C-H伸缩振动,饱和C-H伸缩振动,饱和Ge-C伸缩振动等特征数据基本一致。C=0伸缩振动在Ramam和IR光谱中位  相似文献   

5.
人乳腺癌组织的特征红外光谱研究   总被引:26,自引:2,他引:24  
应用傅里叶变换红外光谱对20例人乳腺病理样品进行了分析。实验发现,乳腺癌组织与乳腺良性病变组织之间有较大的红外光谱差异。与乳腺良性病变组织比较,乳腺癌组织的红外光谱中磷酸二酯基团反对称伸缩振动向短波方向位移了2cm^-1,其对称伸缩振动向短波方向位移了3cm^-1,C-O伸缩振动吸收A1173/A1163比值增加,A1025/A1082比值下降;CH3的反对称及对称伸缩振动减弱,CH2的对称及反对  相似文献   

6.
C8H8O7H2O单晶的振动光谱李丽霞(山东大学环境工程系济南250100)TheVibrationalSpectrumofC8H8O7H2OCrystalLiLiXia(EnvironmentalEngineringDepartment,Shand...  相似文献   

7.
氟原子与氯溴代甲烷反应的光谱及动力学研究   总被引:1,自引:0,他引:1  
本文报导了氯原子与三种含氢氯溴代甲烷(CH2BrCl,CHBrCl2,CHBr2Cl)反应的光谱及动力学研究结果,观察了这些反应的可见化学发光(300-900nm)和染料R6G波段(565-610nm)的激光诱导荧光,观测到HF基电子态振动泛频跃迁和Br2(A,B),BrF(B)分子电子激发态跃迁的发射谱以及BrF(X),CHF(X)的基电子态的激发谱,计算机模拟光谱求出了Br2(B),BrF(X  相似文献   

8.
胃癌组织的拉曼光谱初探   总被引:14,自引:2,他引:12  
本文用FT-Raman光谱方法研究了40例胃癌与胃正常组织,所得的光谱经统计处理的发现,肿瘤光谱中水、蛋白质有关的OH(NH)伸缩振谱带,C=O伸缩振动,H-O-H变角振动谱带明显强于正常组织的光谱,造成这一现象的原因可能是水与蛋白相互作用及氢键结构在正常组织和肿瘤组织中不同所致。  相似文献   

9.
高重复频率实时采集的光腔衰荡光谱   总被引:8,自引:3,他引:5  
建立了一套脉冲激光衰荡光谱实验信号采集与处理系统。它以GPIB为控制和数据传输的界面,采用比国际上同类实验更合理严格的方式采集处理数据,实现了高重复频率、实时的波形信号传输、显示和处理。利用此装置测量了H2O从620 ̄665nm的振动泛频光谱,实验结果表明,该装置检测灵敏度达到5×10^-8cm^-1。  相似文献   

10.
用最小二乘法拟合CH3D分子6428cm^-1附近振动带的138个能级,10个振动常数。振动分析阐明带为CH3分子C-D对称伸缩振动3V2态,并与局域模振动理论计算值进行了比较。  相似文献   

11.
应用分子动力学模拟方法研究了液相水中水分子O-H弯曲振动能量弛豫的机理. 采用刚性和柔性溶剂模型来探讨振动能量弛豫的不同通道. 研究发现,刚性溶剂中O?H弯曲振动泛频的弛豫时间为174 fs而柔性溶剂中为115 fs. O-H 弯曲振动泛频振动能量弛豫的主要途径是跃迁O?H 弯曲振动基频. O-H弯曲振动基频的弛豫时间为204 fs,与实验值170 fs符合得较好.  相似文献   

12.
We performed, in the O-H stretching region, Fourier-transform Infrared (FT-IR) Absorption measurements for investigating the vibrational dynamics on water confined in NaA zeolite, vs. temperature and for different hydration percentages. The spectral substructure of the O-H stretching band is explained postulating the existence of three major components centred at approximately 3290 cm(-1) (omega(1)), approximately 3470 cm(-1) (omega(2)), approximately 3590 cm(-1) (omega(3)), with different dynamical properties traced over the full T-range investigated.  相似文献   

13.
对四种不同的实验构型下空气/水界面自由O-H键在3700cm~(-1)的和频振动光谱的分析表明,水分子在空气/水界面的取向运动只可能是在平衡位置附近有限角度之内的受限转动。界面水分子的自由O-H键取向距界面法线约33°,而取向分布或运动的宽度不超过15°。这一图像显著地不同于Wei等人(Phys. Rev. Lett.86,4799(2001))只通过单一的SFG实验构型所得出结论,即:空气/水界面的水分子在超快的振动弛豫时间内在很大的角度范围内运动。  相似文献   

14.
Abstract

The Fourier transform (FT) infrared and Raman spectra of newberyite, MgHPH4 - 3H2O are studied in the region where the stretching vibrations of the water molecules (protiated and deuterated) and the O-H/O-D stretches of the hydrogenphosphate anions are expected to appear. The O-H stretching vibrations give rise to a complex feature known as the A,B,C trio. Since neither of the maxima found below 3000 cm?1 represents a true band arising from a given fundamental, it is pointless to correlate their frequencies with the observed O…O distances. In the water stretching region, the two bands with highest frequencies undoubtedly correspond to the anti symmetric and symmetric stretch of one type of the water molecules. The stretching vibrations of one of the remaining two types of H2O molecules are clearly uncoupled and the O-H oscillator involved in the weaker hydrogen bond is responsible for a band at 3376 cm?1 whereas the rest of the water stretchings are apparently overlapped yielding the complex band below 3320 cm?1. Thus the situation is again complicated and the correlations between the frequencies and the Ow…O distances are inappropriate. The two bands at highest frequencies (3522 and 3483 cm?1 at RT) exhibit a positive temperature coefficient.

  相似文献   

15.
费米共振现象是一种广泛存在于分子振动光谱中的现象,特别是结构比较复杂的多原子分子.在多原子分子中当振动倍频或组合频位于某一基频附近,由于发生振动耦合,会出现两个新峰,峰的位置向两侧发生移动,二者谱线强度发生变化,把这种现象称为费米共振.费米共振现象不仅存在于红外光谱中,也存在于拉曼光谱中.文章中测量了CCl4的拉曼光谱,利用所得到的谱线峰位和用Originpro7.5软件程序获得积分强度,用费米共振的相关理论计算了C-Cl的a1对称伸缩振动频率v1与C-Cl2的f对称弯曲振动频率v4的组合频(v1 v4)与(某一未知基频)C-Cl的f对称伸缩振动频率v03的费米共振特征参数,进而计算出了耦合系数W和这一未知基频v03.该文对理解费米共振,了解分子振动频率,研究分子结构有很重要的参考价值.  相似文献   

16.
The ground state hydrogen conformations and vibrational analysis of 3-deazauracil (3DAU) and 6-azauracil (6AU) tautomers (4-enol and 2,4-diol forms) have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-311++G(d,p) basis set level. The calculations have shown that the most probably preferential tautomer of 3DAU and 6AU are the 4-enol form, which gives best fit to the corresponding experimental data. The ground state conformer of the 2,4-diol form has two O-H bonds which are oriented externally and internally (to the N-H bond). The vibrational analyses of the ground state conformer of each tautomeric form of 3DAU and 6AU were done and their optimized geometry parameters (bond lengths and bond angles) were given. Furthermore, from the correlations values it was concluded that the B3LYP method is superior to the HF method for both the vibrational frequencies and the geometric parameters.  相似文献   

17.
In this paper, we introduce one dimensional vibron model to analyze the fundamental, overtone and combination modes of CF4 molecule and both stretching, bending vibrational mode of bent H2O molecule up to first overtone with few algebraic parameters. Using the model Hamiltonian, we reported here better results for the vibrational spectra of H2O. Our analysis suggests some reassignments of levels and predicts location of states in case of CF4 molecule which was not yet observed.  相似文献   

18.
对甲氧基苯甲腈是一种重要的化学化工原料,本文采用超声分子束技术和共振多光子电离方法获得了对甲氧基苯甲腈的单色共振双光子电离光谱,基态S0到电子激发态S1的0←0跃迁被确定为(35549±2)cm~(-1),结合含时密度泛函理论计算结果对观察到的光谱进行了振动模式标识和描述.实验发现呼吸振动模非常易于激活,其基频和二次泛频光谱很强,三次泛频也可明确标识,观察到大量呼吸振动与其他正则模的结合振动,这是对甲氧基苯甲腈不同于常见的多原子分子的一个重要特性.这些结果为研究对甲氧基苯甲腈的里德堡态、动力学和零动能光谱等提供了重要的参考数据.  相似文献   

19.
Theoretical approximations to the sum frequency vibrational spectroscopy (SFVS) of the carbon tetrachloride/water interface are constructed using the quantum-corrected time correlation functions (TCF) to aid in interpretation of experimental data and to predict novel vibrational modes. Instantaneous normal mode (INM) methods are used to characterize the observed modes leading to the TCF signal, thus providing molecular resolution of the vibrational lineshapes. Detailed comparisons of the theoretical signals are made with those obtained experimentally and show excellent agreement for the spectral peaks in the O-H stretching region of water. An intermolecular mode, unique to the interface, at 848 cm(-1) is also identifiable, similar to the one seen for the water/vapor interface. INM analysis reveals the resonance is due to a wagging mode (hindered rotation) that was previously identified (Perry et al 2005 J. Chem. Phys. 123 144705) as localized on a single water molecule with both hydrogens displaced normal to the interface-generally it is found that the symmetry breaking at the interface leads to hindered translations and rotations at hydrophilic/hydrophobic interfaces that assume finite vibrational frequencies due to anchoring at the aqueous interface. Additionally, examination of the real and imaginary parts of the theoretical SFVS spectra reveal the spectroscopic species attributed the resonances and possible subspecies in the O-H region; these results are consistent with extant experimental data and associated analysis.  相似文献   

20.
A high-resolution vibration-rotation overtone spectrum of H13C12CH has been recorded with a Fourier transform infrared spectrometer in the wavenumber region 6400 to 6700 cm−1. The main band, assigned as the C-H stretching combination band ν13, and some overtone and hot bands have been rotationally analyzed. Altogether eight parallel bands have been observed. The vibrational labels have been deduced on the basis of the assignments of the fundamental ν3 antisymmetric C-H stretching band system.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号