Spectral Studies on Some Pyrimidine Derivatives in Different Solvents

The electronic absorption spectra of 2-aminopyrimidine (compound I), 2-amino-4-methylpyrimidine (compound II), 2-amino-4,6-dimethylpyrimidine (compound III), 2-amino-4,6-dimethoxypyrimidine (compound IV), 4-amino-2,6-dimethylpyrimidine (compound V), and 4,5-diamopyrimidine (compound VI) have been measured in water and in a series of different organic solvents. The solvent effects on the spectra are discussed and the solvent induced spectral shifts are analyzed in terms of different solute–solvent interaction mechanisms, using the multiple linear regression technique.     

Study on the interaction of amino phosphine ester derivatives with DNA by spectroscopy, modeling and calorimetry

The binding properties of amino phosphate ester derivatives, compound 1 and 2 with calf thymus DNA (CT-DNA) were investigated by UV spectra, fluorescence spectra, molecular modeling and isothermal titration calorimetry (ITC). The intrinsic binding constants K_b of compound 1 and 2 with CT-DNA were determined by fluorescence spectroscopy and ITC, respectively. The results indicated that the two compounds bind to CT-DNA with different binding affinity, which is in the order of compound 1 > compound 2. At the same time, fluorescence spectra suggested that the mechanism of the binding of the two compounds to CT-DNA is a static enhancing type. According to the ethidium bromide displacement experiments, UV spectra, molecular modeling and ITC studies, it can be concluded that compound 1 and 2 are intercalators that can slide into the G–C rich region of CT-DNA. Furthermore, ITC data showed that compound/DNA binding is enthalpy controlled.     

四氟菊酯的核磁共振法分析

采用^1HNMR、^13C NMR、无畸变增强极化转移实验(DEPT)、^1H—^1H相关谱(COSY)、^1H检测异核多量子相关谱(HMQC)、^1H检测的异核多键相关谱(HMBC)等方法，对四氟菊酯的^1H和^13C NMR谱信号进行了归属；并用奥氏核效应(NOE)差谱法确定了该化合物的立体结构，为其结构鉴定和生产过程中的质量控制提供了重要依据。     

Oxonol 染料的稳态光物理行为研究

对oxonol——一种带负电荷类菁染料化合物溶液的光谱和光物理问题进行了研究.发现它和一般分子内共轭的电荷转移化合物相比，无论在吸收光谱或荧光发射光谱上，都表现出不同的光物理和光化学行为.对出现的这种差异，特别是负的溶致变色行为和在不同pH条件下分子的互变异构等对吸收光谱的影响进行了讨论.     

2-(2-羟基-5-氯苯基)-1H-苯并咪唑-铜(Ⅱ)配合物作为NO荧光探针的初探

常温下合成了2-(2-羟基-5-氯苯基)-1H-苯并咪唑荧光化合物和其二价铜离子的配合物,并对配合物的结构和稳定性进行了表征,用荧光光谱、质谱、红外光谱等研究了配合物与NO反应的机理.结果表明,该配合物与NO的反应具有高度的选择性,不受其他常见干扰分子的影响.配合物应用于脂多糖(LPS)激活的小鼠巨噬细胞中NO的测定,能够得到具有较好分辨率的荧光成像结果.     

Synthesis and spectroscopic study on photochromism of a new thiosemicarbazone compound containing pyrazolone

A new photochromic compound 1,3-diphenyl-4-(4'-fluro)benzal-5-pyrazolone-4-ethyl thiosemicarbazone (DP4FBP-ETSC) was synthesized by direct condensation of 1,3-diphenyl-5-pyrazolone with N4-ethyl thiosemicarbazide. The product was characterized by elemental analysis, IR and 1H NMR spectra. The photochromic properties of the compound were studied using time-dependent fluorescence emission spectra, the UV-vis reflection spectra in the solid state and the UV-vis absorption spectroscopy in liquid. The reaction rate constant of compound was also analyzed. The results show that DP4FBP-ETSC can perform photochromism.     

Deconvolution of lignin fluorescence spectra: A contribution to the comparative structural studies of lignins

In this work, we deconvoluted the fluorescence spectra of lignin and a lignin model compound using a combination of one symmetric (Gaussian) and the most appropriate number of asymmetric (Log-normal) models. We aimed to obtain new data on the structural characteristics of lignin as a complex molecule using fluorescence spectroscopy in combination with FTIR spectra. We analyzed the emission spectra of the lignin model compound, DHP, and isolated lignins from a deciduous tree, poplar, and a coniferous tree, spruce. The number of applied asymmetric components was varied for each sample until the component positions obtained from deconvolution of a series of spectra became constant. The lignin model compound contains fewer components in the emission spectrum. The same components in the spectra of all three samples show that they contain the same fluorophores. The small shift of the peak position can be attributed to the influence of different environments. The FTIR spectra of the three polymers show a small difference between their structures. The main difference among the IR spectra of the three samples is in the intensity of some peaks. The text was submitted by the authors in English.     

含吡唑基的苯骈咪唑的合成与光谱性能(英文)

在乙醇溶剂中,于温和条件下以邻苯二胺和1-苯基吡唑-4-醛为原料合成了一种结构新颖的含吡唑取代基的苯骈咪唑杂环化合物,通过元素分析,MS,1H NMR对所合成的苯骈咪唑化合物的组成与结构进行了表征,同时对该化合物的紫外-可见光谱和荧光光谱进行了研究.     

[NH3Pr^i]6[Mo8O28(CHO)2].2H2O单晶紫外光照后的电子顺磁共振研究

本文研究了[NH3Pr^4]6[Mo8O28(CHO)2].2H2O单晶在紫外光辐照后的电子顺磁共振谱法. 观察到三组包含质子超精细结构的EPR谱线. 线组I和II分别归属于正文文中局部八面体顺磁中心A和B, 而线组III则可能归属于一种不稳定的顺磁中心.从EPR数据使用最小二乘拟合技术得到了精确的各向异性g张量主值、A张量主值,以及它们的主轴相对于实验坐标的方向余弦. 由A值估算了电子自旋密度. 结果表明Mo未成对电子主要处于Mo的d轨道, 并与H原子轨道发生直接偶合作用.     

酰胺基卟啉的制备,光谱及电化学性质研究

合成了未见文献报道的5-(4-异烟酸酰亚胺基)苯基-10,15,20-三苯基卟啉配体(H2P)及其锌配合物(ZnP),并通过紫外-可见光谱、红外光谱、核磁共振氢谱、元素分析等测试方法对化合物的结构加以确认.研究表明,配体和配合物的拉曼光谱有很大区别,卟啉配体的循环伏安曲线与氨基卟啉和锌配合物不同,卟啉环的氧化还原峰位都有移动.差热研究表明,卟啉配体410oC开始分解,显示了很高的热稳定性.     

Vibrational analysis of 2-[4-(<Emphasis Type="Italic"> N</Emphasis> -dodecanoylamino)phenyl]-5-(4-nitrophenyl)-1,3,4-oxadiazole

The infrared absorption spectra of 2-[4-( N -dodecanoylamino)phenyl]-5-(4-nitrophenyl)-1,3,4-oxadiazole (also denoted AF51) in solution and in the solid state as well as the solid-state Raman spectrum of the powdered compound are compared with the infrared linear dichroic (LD) spectra recorded at two orthogonal polarizations. The IR-LD spectra were measured in an anisotropic solvent-the nematic liquid crystal ZLI-1695 (Merck). The solvent spectrum taken under precisely the same experimental conditions and polarized radiation azimuths was subtracted from the polarized sample spectra in order to achieve pure oriented spectra of the compound studied. These spectra were further processed using a stepwise reduction procedure that allows for assignment of vibrational modes having mutually orthogonal dipole moments.     

双吲哚啉螺吡喃化合物的合成及其酸和金属离子致变色性能

设计、合成了一种新型双吲哚啉螺吡喃化合物1,用核磁、红外及质谱等技术手段表征了其结构。 利用紫外可见吸收光谱研究了化合物1的酸致变色和金属离子变色性能。 结果表明,化合物1能够在氢离子或金属离子的作用下发生可逆的开环与闭环反应。 当氢离子或金属离子加入到化合物1的异丙醇溶液中,溶液颜色从无色变为红色,同时产生460 nm新吸收峰。 进一步加入氢氧根离子或EDTA溶液后,溶液颜色变回无色,460 nm处的吸收峰又消失。 该化合物的酸和金属离子致变色性质在分子传感和离子识别等领域有潜在的应用价值。     

对-羟基苄叉丙二腈溶液在不同pH条件下吸收光谱的变化

在苄叉丙二腈衍生物系列中,N,N-二烷基氨基苄叉丙二腈及其类似化合物是研究和应用较多的一类。它们曾作为分子探针应用于高分子微环境特性和高分子聚合过程的研究。作为一种分子内的电荷转移络合物,它们在不同溶剂中的光谱行为也进行过研究,从而为进一步的开拓应用提供了重要依据。和前者相比,对-羟基苄叉丙二腈无论在基础研究或实际应用上都显得比较薄弱。正因如此,本工作合成了该化合物并对它进行了初步研     

Molecular structure and vibrational spectra of phenobaraitone by density functional theory and ab initio hartree-Fock calculations

Quantum chemistry calculations have been performed using Gaussian03 program to compute optimized geometry, harmonic vibrational frequency along with intensities in IR and Raman spectra at RHF/6-31++G** and B3LYP/6-31++G** levels for phenobarbitone (C₁₂H₁₂N₂O₃) in the ground state. The scaled harmonic vibrational frequencies have been compared with experimental FT-IR and FT-Raman spectra. Theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions (PEDs) using MOLVIB program. A detailed interpretation of the infrared spectra of the title compound is reported. On the basis of the agreement between the calculated and observed results, the assignments of fundamental vibrational modes of phenobarbitone were examined and some assignments were proposed. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title compound have been constructed.     

11, 12-Dihydro- 12-hydroxy-tribenzo[c,g,m]-1,2,5,6,9,12-hexa-azacyclotetradecine; a Neutral Homoaromatic [14]Annulene Macrocyclic Aza Compounds,I

The structure of the title compound 2 is supported by spectra and analysis; homoaromaticity is deduced from its NMR. and electronic spectra.     

NMR Parameters and Vibrational Investigation of 2-Dicyanovinyl-5-（4-ethoxyphenyl） thiophene by ab initio HF and DFT Calculations

Optimized geometry and harmonic vibrational frequency of 2-dicyanovinyl-5-(4- ethoxyphenyl)thiophene (C16H12N2OS) are calculated at the HF/6-31++G(d,p) and B3LYP/6- 311++G(d,p) levels. Mulliken charges in the ground state are also calculated. The research shows the presence of intermolecular interaction in the title compound. The scaled harmonic vibrational frequencies have been compared with experimental FT-IR spectra. A detailed interpretation of the infrared spectra of the title compound is reported. The theoretical spectrograms for IR spectra of the title compound have been constructed. The isotropic chemical shift computed by 13C and 1H NMR analyses also shows good agreement with the experimental observations.     

含穴醚N8O3配体的金属大环化合物的NMR研究

在溶液中,室温下对含有穴醚Ｎ８Ｏ３配体（Ｈ３Ｌ）的金属大环化合物［Ｎａ（Ｈ３Ｌ）］（ＣｌＯ４）３Ｈ２Ｏ（２）和［Ｌａ（Ｈ３Ｌ）（ＯＨ）２］（ＣｌＯ４）３（３）,作了１ＨＮＭＲ谱的测定,在化合物（２）－乙腈溶液中加入过量Ｌａ（ＣｌＯ４）３后的（２＋Ｌａ）和化合物（３）还作了１３Ｃ和１Ｈ－１ＨＣＯＳＹ（氢－氢相关二维谱）、１Ｈ－１３ＣＨＭＱＣ（氢核检测的异核多量子相干相关谱）及１Ｈ－１３ＣＨＭＢＣ（氢核检测的异核多键相关谱）的ＮＭＲ谱测定,归属了所有１Ｈ,１３Ｃ的谱线。对其配位行为通过１ＨＮＭＲ试验作了简单的讨论。     

Infrared optical properties and Raman spectra of n-pentane and n-pentane-d12

Infrared and Raman spectra have been collected and analyzed for n-pentane and n-pentane-d₁₂. The real (n) and imaginary (k) refractive index spectra for each compound have been calculated from the experimental infrared spectra after determining the refractive indices of n-pentane across the visible region of the electromagnetic spectrum. To further aid in the study, the imaginary polarizability (IP) spectrum for each compound was calculated from the n and k spectra, then curvefit to separate intensities. Computational DFT calculations were performed to create theoretical spectra of each compound, which in turn aid in assigning vibrations in the experimental spectrum. Barriers to rotation for n-pentane were explored to determine the dominant conformations.     

3-(3′-吡啶基)-6-芳基-1，2，4-三唑并[3，4-b]-1，3，4-噻二唑衍生物基态和激发态性质

用密度泛函B3LYP方法对3-(3'-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物(芳基为苯基、3-吡啶基和苯乙烯基)进行基态几何构型全优化,计算分子的电离势I_p和电子亲和势E_A等相关能量,并用Zerner间略微分重叠(ZINDO)和含时密度泛函(TDDFT)方法计算吸收光谱,用单组态相互作用方法(CIS)优化三种化合物分子的S_1激发态结构,分析其能量与发射光谱的关系,计算溶剂中分子的吸收和发射光谱,并与实验结果对照.计算结果表明,从3-(3'-吡啶基)-6-苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物A)到3-(3'-吡啶基)-6-(3'-吡啶基)-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物B)以及3-(3'-吡啶基)-6-对乙烯苯基-1,2,4-三唑并[3,4-b]- 1,3,4-噻二唑分子(化合物C)的电子亲和势依次增大,愈来愈容易接受电子,吸收光谱和发射光谱红移.     

有机银溶胶的吸收光谱和表面增强Raman光谱研究

研究了2-氨基苯并咪唑(BIMNH₂)、LiCl、NaOEt对Ag/EtOH溶胶吸收光谱和表面增强Raman散射(SERS)光谱的影响。结果表明,少量的吸附分子BIMNH₂、LiCl、NaOEt均能改变溶胶聚集状态,从而影响其吸收光谱和SERS效应。此外,Cl^-还可与Ag、BIMNH₂形成表面络合物而增强SERS效应。对Ag溶胶体系SERS光谱的溶剂效应也作了初步研究。