2-氨基-5-甲硫基-1,3,4-噻二唑的FT-IR,FT-Raman和共振拉曼光谱指认

利用共振拉曼光谱技术以及密度泛函理论(DFT)计算对2-氨基-5-甲硫基-1,3,4-噻二唑(5-AMTT)在Franck-Condon区域的光诱导激发态短时动力学进行了研究。通过实验获得了5-AMTT固体的FT-IR和FTRaman光谱,并结合量子化学计算确认了5-AMTT的稳定构型。获得了5-AMTT在乙腈、甲醇和水溶剂中309.1nm激发波长下的共振拉曼光谱图。共振拉曼光谱可以被指认为9个Frank-Condon活性振动模的基频、倍频和它们的组合频,其中5-AMTT环上C5N4的伸缩振动、CH3上C—H的振动以及NH2的振动的基频、倍频和组合频占据了其主要吸收带共振拉曼光谱强度的绝大部分,表明5-AMTT激发态结构动力学主要沿着这些反应坐标展开。

不同化学处理方法对竹纤维化学成分的影响

采用硝酸+氯酸钾、双氧水+冰醋酸、次氯酸钠和氢氧化钠四种化学处理方法及超声和无超声两种处理条件对慈竹(Neosinocalamus affinis)进行分离得到竹纤维,利用傅立叶变换红外光谱(FT-IR)和傅立叶变换拉曼光谱(FT-Raman)定性研究不同方法制取竹纤维的化学成分变化、分离过程中超声波处理对竹纤维化学成分的影响。结果表明:四种处理方法对纤维素的影响不明显;硝酸+氯酸钾、次氯酸钠和氢氧化钠制取的竹纤维中都含有小质素,但含量不同,双氧水+冰醋酸制取的竹纤维几乎不含木质素;四种处理方法都降解了半纤维素,但降解程度不同。在纤维分离过程中,超声处理能够缩短纤维分离时间,提高纤维分离效率,同时对纤维化学成分影响不明显。

Vibrational Spectroscopic Study of N-[4-[1-Hydroxy-2-[(1-Methyl Ethyl)Amino]Ethyl]Phenyl]Methane Sulfonamide

The vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 4 000~400and 4 000~400cm-1 respectively,for N-[4-[1-hydroxy-2-[(1-methyl ethyl)amino]ethyl]phenyl]methane sulfonamide(HPAEPMS)molecule.Theoretical calculations were performed by ab initio Density Functional Theory(DFT)method using 6-31G(d,p)basis set.The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution(PED).The results of the calculations were applied to simulated spectra of the title compound,which show excellent agreement.

炸药化学标记物DMNB的合成方法与标识特性

为应对公共安全领域爆炸恐怖袭击威胁,增加可塑性炸药的安检检出率,对炸药化学标记物DMNB的合成方法进行了实验研究,对一步法和二步法合成DMNB技术途径的原理和产出率等进行了对比。确定了相转移法氯代偶合二步合成DMNB为优选方案,并分别用GC-MS、FT-IR、FT-Raman表征DMNB的标识特性和结构。实验结果表明,DMNB在不同检测环境下具有易被现有检测分析仪器快速检出的明确标志性信息,具有明显的标识特性,可满足低挥发性炸药标记物的基本要求,且用氯代-偶合法合成DMNB,具有产出率高、纯度高和成本低的特点,有利于进一步开展DMNB作为低挥发性炸药标记物的实用化研究。

Vibrational Spectroscopic Investigation and DFT Calculations on the Decabromodiphenyl Ether

Decabromodiphenyl ether （BDE-209）, the major congener in the high volume industrial flame retardant mixture ＂DecaBDE＂, has become a ubiquitous environmental contaminant. In the present work, combined experimental and theoretical studies have been undertaken on the structure and vibrational spectra of BDE-209. The FT-IR （400-4000 cm-1） and FT-Raman spectra （100-4000cm-1） of BDE-209 were recorded, while density functional B3LYP calculations were employed in conjunction with the 6-31G（d） basis set for investigating the corresponding geometric structure and vibrational spectroscopic properties. Besides, the detailed interpretations of fundamental vibrations were performed on the basis of experimental results and potential energy distribution （PED） of the vibrational modes. Optimized structures of the title compound were interpreted and compared with the earlier reported experimental values, which yield good agreement. Finally, the measured and calculated harmonic vibrational wavenumbers were compared with each other, and they were found to be in good accordance.

Spectroscopic Investigation of Black Pepper （Piper nigrum L.）

Black pepper （Piper nigrum L.） is an extensively used medicinal plant in Ayurvedic medicine since ancient times. Here we present Fourier transform infrared （FT-IR） and Fourier transform Raman （FT-Raman） spectra of black pepper powder, which reveal the presence of some specific functional groups, attributed to the different vibrational bands present. Through the assignment of the vibrational bands, black pepper is shown to have enough carboxyl dimer character, a feature that could make it effective in the treatment of the deadly disease vitiligo. Mineral composition reported with the help of XRF spectra strengthens this.

Vibrational and Electronic Spectra of 2-Phenyl-2-Imidazoline: A Combined Experimental and Theoretical Study

The structural properties and vibrational frequencies of 2-phenyl-2-imidazoline have been investigated using theoretical and techniques by which a good correlation was observed. The assignments of the vibrational modes were performed with the help of normal co-ordinate analysis following the Scaled Quantum Mechanical Force Field methodology. Natural bond orbital analysis and the highest occupied molecular orbital-lowest unoccupied molecular orbital gap analysis have been carried out. UV-visible spectrum of the compound was recorded and compared with the theoretical UV-visible spectrum of the title molecule using Symmetry Adapted Cluster-Configuration Interaction method which yielded good agreement. Our results reflect that the title compound can be used as good source of UV light.

Vibration spectroscopic technique for species identification based on lipid characteristics

Due to the widespread of adulteration of lipid in food and feed industry,the quality and safety of lipid are of public concern gradually.Firstly,the current article presents theory and mechanism of species identification of lipid by spectroscopic technique.Potential of near-infrared reflectance spectroscopy(NIR),Fourier transform infrared spectroscopy(FT-IR),and Fourier transform Raman spectroscopy(FT-Raman)applied to species identification of lipid were summarized.In addition,the relationship between lipid and spectroscopy as well as the recent advances of species identification of lipid were discussed.Research showed that FT-IR and FT-Raman spectroscopies possessed more efficient potential for species identification of lipid.Finally,prospects for future lipid detection and relative practical application,and combination of spectroscopy and other technique were further discussed.

Cytotoxicity of new Ho(Ⅲ) and Pr(Ⅲ) complexes

New complexes of coumarin-3-carboxylic acid(HCCA) with Ho(Ⅲ) and Pr(Ⅲ) were synthesized and their structures and spectral properties were investigated by elemental analysis,IR,Raman and NMR measurements.According to the experimental data the complexes’ formula and geometries were suggested.Vibrational frequencies,IR intensities and Raman activities as well as 1H NMR chemical shifts of HCCA and its Ho(Ⅲ) and Pr(Ⅲ) complexes were presented.The comparative experimental vibrational and NMR analyses of both the ligand and the Ln(Ⅲ) complexes predicted the bidentate binding to Ho(Ⅲ) and Pr(Ⅲ) through the deprotonated carboxylic oxygen and the carbonylic oxygen of the ligand.The cytotoxic/cytostatic properties of the ligand and the newly synthesized complexes of coumarin-3-carboxylic acid with Ho(Ⅲ) and Pr(Ⅲ) were tested by MTT reduction assay against two mouse tumor cell lines:melanoma B16 and fibrosarcoma L929.They were also tested for cytotoxicity against normal mouse peritoneal macrophages.The proliferation inhibitory effect of the complexes compared to that of the ligand proved their cytotoxic/cytostatic properties against both the tumor cell lines.In addition,the complexes were less cytotoxic against normal mouse macrophages and were able to modulate NO release by activated macrophages.The obtained results were in accordance with our previously published data concerning the activity of lanthanide(Ⅲ) complexes with other coumarin derivatives.