傅里叶变换红外光谱分辨率与氯仿测量精度的关系

测量不同分辨率下、不同浓度氯仿气体的傅里叶变换红外光谱（FTIR）．利用美国环境保护局（EPA）数据库中的数据,通过最小二乘拟合得到不同分辨率下的氯仿浓度,以及线性拟合度和相对误差．分辨率的大小对其计算精确度有一定的影响．选择合适的分辨率对于提高化合物的精确度至关重要．     

Curing kinetics of the epoxy system diglycidyl ether of bisphenol A/isophoronediamine by Fourier transform infrared spectroscopy

The curing reaction of an epoxy system consisting of a diglycidyl ether of bisphenol A (BADGE, n = 0) and isophoronediamine (IPD), was studied by Fourier transform infrared spectroscopy (FTIR). The degree of conversions and the reaction rates at different isothermal curing temperatures were calculated from the infrared spectra using a method derived from Beer's law. This method is based on the ratio of the height of the characteristic absorbance peak to reference absorbance peak. A kinetic model proposed by Sourour and Kamal has been used to fit experimental data. Copyright © 2008 John Wiley & Sons, Ltd.     

Supramolecular systems based on the melamine salt of bis(hydroxymethyl)phosphinic acid (melafen) dihydrate and surfactants

Bis(hydroxymethyl)phosphinic acid and melamine were shown by FTIR and UV spectroscopy to form the salt (melafen), whose cations and anions involving water molecules can be joined into supramolecular structures due to electrostatic interactions and hydrogen bonds. The conductometry, dielcometric titration, and dynamic light scattering methods showed that melafen in water and chloroform in a concentration range of 10⁻¹⁰–10⁻⁴ mol L⁻¹ involving the solvent structures exist as supramolecular polymeric nanostructures, whose size and properties change nonlinearly depending on the melafen concentration. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1207–1214, June, 2008.     

Identification of five <Emphasis Type="Italic">Listeria</Emphasis> species based on infrared spectra (FTIR) using macrosamples is superior to a microsample approach

Microorganisms can be identified using both macrosamples and microsamples based on infrared spectra (FTIR). This work compares the identification of the five closely related Listeria species L. innocua, L. ivanovii, L. monocytogenes, L. seeligeri, and L. welshimeri using both methods. The overall identification success for 25 strains was 92.8% for the former and 79.2% for the latter methods, respectively. The worst performances of the microsample method were obtained for L. innocua, L. ivanovii, and L. monocytogenes, while L. seeligeri and L. welshimeri did not show significant differences between the techniques. Identification success was mainly influenced by the age of the cells and the spatial heterogeneity of the microcolonies, as analyzed by the microsample method. Spectra of Listeria cells near the stationary phase exhibited more species-specific markers and thus allowed for better discrimination than spectra of growing cells. Furthermore, the heterogeneity of cell composition at different locations in microcolonies of L. innocua, L. ivanovii and L. monocytogenes resulted in limited discrimination success of the microsample method. We conclude that, at least in the case of Listeria, the macrosample method is superior to the microsample method, although the latter is the faster technique.     

Computational,structural, spectral,optical and Hirshfeld surface analysis of (E)-2-(3,4,5-trimethoxybenzylidene) hydrazinecarbothioamide (ETMBHC): Third order NLO single crystal

By using a slow evaporation solution growth technique, single crystals of (E)-2-(3,4,5-trimethoxybenzylidene) hydrazine carbothioamide (ETMBHC) have been produced. The crystalline compound has the following properties: a = 7.471 (3), b = 9.705 (4), c = 11.168 (4), = 73.200(11)°, = 70.633 (10)°, = 70.334 (10)°; it belongs to the triclinic system with space group P. The ETMBHC chemical is a member of the P-1 triclinic system. Fourier transformations and Fourier transform infrared (FT-IR) The functional groups have been identified by Raman spectrum research. To understand how charge transfer occurs inside molecules and to establish that the title crystal is appropriate for NLO applications, the HOMO and LUMO energies for the grown crystal were computed. TGA-DTG analysis was used to study the melting point and thermal stability. Z-scan analyses were used to determine the grown crystal's nonlinear absorption coefficient and third-order nonlinear refractive index.     

Spectroscopic study of the degradation products in the holy water fonts in Santa Maria della Steccata Church in Parma (Italy)

Two holy water fonts (dated at the beginning of the XVII century) in the Santa Maria della Steccata Church in Parma (Italy) have recently been restored. Before the intervention, a detailed investigation on their degradation products was carried out to understand the mechanisms of alteration of the materials and to suggest appropriate restoration procedures.The analyses were performed by means of powder X-ray diffraction (XRD), micro-Fourier transform infrared (FTIR) and micro-Raman spectroscopies. Calcite, iron oxides, silicates and sodium chloride (from salted holy water) were found in the red coloured calcarenite. On and under the lead coverings, different lead oxides (mainly massicot), other lead salts (lead basic carbonate, cerussite, plumbonacrite Pb₁₀O(OH)₆(CO₃)₆ and lead-chlorine compounds as laurionite PbOHCl and phosgenite Pb₂CO₃Cl₂) were identified by Raman spectroscopy and XRD. Haematite α-Fe₂O₃, goethite α-FeO(OH) and lepidocrocite γ-FeO(OH) were found on and around the iron hinges.Lead compounds and sodium chloride, through crystallization and solubilization cycles, were responsible for the stone's degradation, whereas the iron corrosion materials on the hinges produced mechanical stress and cracks in the stone.Various suggestions have been given on how to restore these fonts and to remove the causes of damage.     

柳树病叶的傅里叶变换红外光谱研究

利用傅里叶变换红外(FTIR)光谱技术对三种柳树正常叶和病叶,同一枝条的幼叶、成叶、黄叶、病叶进行光谱测试,旨在分析柳树病叶发生的一些生理变化,并探讨柳树病变对系统聚类的影响。谱图显示不同阶段的叶片光谱变化主要在1800~800cm-1。对此波段进行二阶导数处理,清晰可看到蛋白质和木质素的叠加区域1700~1500cm-1,草酸钙特征峰1621、1318cm-1,糖类特征峰1075cm-1附近峰强有明显变化,用吸光度比A1621/A3390、A1318/A3390、A1075/A3390来比较草酸钙和糖类相对含量变化,用1700~1500cm-1波段的拟合峰面积比S酰胺I/S木质素、S酰胺Ⅱ/S木质素和S酰胺Ⅱ/S酰胺I来比较蛋白质相对含量变化。结果显示,病叶的草酸钙相对含量增加、多糖和蛋白质相对含量在减少。将叶片1800~800cm-1范围的二阶导数进行系统聚类,发现病叶化学成分的改变没有影响聚类效果,聚类正确率达100%。     

Basicity of trifluoromethylsulfonylformamidines. DFT and FTIR study and NBO analysis

The effect of the electron–acceptor substituent CF₃SO₂ at the imine nitrogen atom on the basicity and the electron distribution in N,N‐alkylformamidines ( 1 , 2 , 3 , 4 , 5 ) was studied experimentally by the FTIR spectroscopy and theoretically at the DFT (B3LYP/6‐311+G(d,p)) level of theory, including the natural bond orbital (NBO) analysis. The calculated proton affinities of the imine nitrogen atom and the sulfonyl oxygen (PA_N′ and PA_O) depend on the atomic charges, the C?N′ and N′―S bond polarity and on the energy of interaction of the amine nitrogen and the oxygen lone pairs with antibonding π* and σ*‐orbitals. The basicity of the imine nitrogen atom is increased with the increase of the electron‐donating power of the substituent at the amine nitrogen atom due to stronger interaction n_N → π*_C?N′, but is decreased for the electron‐withdrawing groups MeSO₂ and CF₃SO₂ at the imine nitrogen atom in spite of the increase of this conjugation. Protonation of ( 1 , 2 , 3 , 4 , 5 ) in CH₂Cl₂ solution in the presence of CF₃SO₃H occurs at the imine nitrogen atom, while the formation of hydrogen bonds with 4‐fluorophenol takes place at the sulfonyl oxygen atom, whose basicity is lower than that of N,N′‐dimethylmethanesulfonamide but higher than of N,N′‐dimethyltrifluoromethanesulfonamide. Copyright © 2015 John Wiley & Sons, Ltd.     

Influence of thickness and annealing on linear and nonlinear optical properties of manganese (III) chloride tetraphenyl porphine (MnTPPCl) organic thin films

Thin films of manganese (III) chloride 5,10,15,20-tetraphenyl-21H,23H-porphine (MnTPPCl) with different film thickness were deposited by an evaporation technique. Some optical constants were calculated for these films at a thickness of 110, 220 and 330 nm and annealing temperature of 373 and 437 K. IR spectrum demonstrating that the thermal evaporation method is a good one to acquire undissociated and stoichiometric MnTPPCl films. Our perceptions demonstrate that the mechanism of the optical absorption obeys with the indirect transition. It was found that the energy gap, E_g, affected by the film thickness and annealing. Dispersion of the refractive index is described using single oscillator model. Dispersion parameters are calculated as a function of the film thickness and annealing temperature. In addition, the third-order nonlinear susceptibility, χ⁽³⁾, and the nonlinear refractive index, n₂, were calculated.     

二维红外相关光谱研究二胺型苯并噁嗪树脂的热固化机理

以原位红外加热附件(in situ FTIR)跟踪二胺型苯并噁嗪树脂的交联固化过程,用二维红外相关光谱(2D-IR)研究其固化机理.In situ FTIR系列图谱显示苯并噁嗪发生热开环反应后,生成的中间体以两种形式存在,含有C N键的中间体不再继续链的增长,其中一部分在高温下发生裂解反应,生成含有亚胺正离子C N+的Schiff碱;含有碳正离子的中间体继续发生交联聚合反应,生成含有羟基、三取代芳香醚和Mannich桥结构的自聚产物.通过2D-IR的分析,进一步给出固化过程中关键基团的变化顺序,确定了二胺型苯并噁嗪树脂的自聚产物结构含有三取代芳香醚和Mannich桥结构.