头孢唑啉酸与稀土元素Eu3+配合物的合成及配位位置的研究

头孢唑啉酸(cefazolin)为抗生素类药物,它的钠盐就是通常所说的先锋霉素. 我们通过共沉淀法合成了头孢唑啉酸与稀土元素Eu³⁺ 的固体配合物,并对其进行了光谱及波谱研究. 通过IR、¹H NMR和¹³C NMR确定了配合物的配位点,并探讨了配位机理.     

红外光谱法研究仲辛醇氧化反应

用红外光谱法研究了浓硝酸氧化仲辛醇合成己酸的反应历程。考察了中间产物硝酸酯，亚硝酸酯，酮类化合物，硝基化合物，有机腈等成分随硝酸用量的变化规律，并对其反应机理进行了探讨。     

Influence of the degree of neutralization of acrylic acid and cross-linking agent on optical properties and swelling of sodium polyacrylate

Optical characteristics of polymerization products under variable degrees of neutralization of acrylic acid (AA) and cross-linking agent and at a fixed content of redox components have been studied by IR spectroscopy of frustrated total internal reflection and THz spectroscopy. The results of the analysis show that absorption of IR radiation and dispersion of THz radiation for the samples under study depend on the degree of AA neutralization, which predetermines the mechanism of structure formation of hydrogels, refractive index, and degree of their limited swelling. It is found that the dependences of the refractive index of dry compact hydrogels and the degree of limited swelling of ground polymer samples on the content of neutralizing agent in solutions of the reaction systems have a symbatic character.     

Electronic state of gold in supported clusters

The electronic states of gold in gold supported nanoparticles modified by Ce, Zr, La and Cs oxides have been studied by the methods of IR spectroscopy of adsorbed CO, UV-visible spectroscopy of diffuse reflectance, XRD and electron microscopy. The additives of Ce and Zr oxides stabilize the ionic states of supported gold and increase the effective charge of the ions. In contrast, La and Cs oxides lower the ion effective charge and favour their fast reduction under redox treatments and reaction medium. It is explained by electron donor-acceptor interaction of the supported metal nanoparticles with the modifiers.     

二维相关红外光谱法研究BMTPF分子光化学反应历程

利用二维相关红外光谱方法首次研究了1,2-二(2’,5’-二甲基-3’-噻吩)-全氟环戊烯(简称BMTPF)在紫外光照引发下发生光化学闭环反应的历程。BMTPF分子的一维红外谱图难以直观反映分子结构的变化情况;而二维相关分析结果清楚地表明:在紫外光照射下,BMTPF开环态分子中噻吩环的芳香性首先减弱,然后才是平面闭环态产物分子的形成。另外,在一维红外谱图中无法分辨的不同取代位置的甲基,在二维相关谱图中,可以清楚地区分开来。与激光光解方法相比,二维相关红外光谱是一种简便而有效的研究手段。     

Investigation of fluorination reactions of the C<Subscript>60</Subscript>Br<Subscript>24</Subscript> bromofullerene with xenon difluoride

The products of the reaction between the C₆₀Br₂₄ bromofullerene and xenon difluoride are studied by IR spectroscopy, laser desorption mass spectrometry, ¹⁹F NMR spectroscopy, and thermogravimetry. It is revealed that the degree of fluorination of the substrate is primarily determined by the duration of contact between the reactants. An attempt is made to perform nucleophilic substitution of fluorine for bromine in the C₆₀Br₂₄ bromofullerene in a solution with potassium fluoride.     

Antireflection Layers for Solar Cells Based on Silicon Nanowires Produced on a Doped Wafer

In this paper, the layers of quantum silicon nanowires produced on highly-doped wafers were studied via the Raman spectroscopy and IR reflection spectroscopy methods. The porosity of layers of different thickness has been determined from IR spectroscopy data using the Bruggeman effective medium model. According to Raman spectroscopy data, the concentration of the free charge carriers in quantum silicon nanowires drops in comparison with that in the wafer. On the basis of these results we conclude that the thickness of a quantum nanowires layer of 2 μm is optimal for its use as an antireflection coating in solar cells. Layers with thicknesses of 10 and 15 μm were studied. It was demonstrated that there is no effect of Raman-scattering enhancement in these layers.     

High‐pressure effects on the Diels–Alder reaction in room temperature ionic liquids

The effect of pressure on the Diels–Alder reaction was examined in room temperature ionic liquids, followed by high‐pressure FT‐IR spectroscopy using pressures up to 150 MPa. Pressure enhances the kinetic sensitivity of the reaction. The kinetic effect of fluorophobic interactions was examined using ionic liquids with fluorous cations. Ionic liquids in combination with ZnI₂ as a Lewis acid catalyst were also studied under high pressure. Copyright © 2007 John Wiley & Sons, Ltd.     

Structural Elucidation of Griseofulvin-2,3-dichloro-5,6-dicyanobenzoquinone Complex

A sensitive spectrophotometric procedure for the estimation of griseofulvin (Antibiotic Ant (fungal) through electron transfer complexation reaction is proposed The pocedure was based on the interaction of the drug oxime with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in acelonitrile media). The optimal experimental conditions, molar ratio of reactants and the applicability of the suggested method to assay the drug in tablet forms were studied. The reaction product was isolated in a crystalline form and subjected to spectroscopic investigation by means of infrared (IR) and electron spin resonance (ESR) spectroscopy. The structure elucidation studies of the complex confirmed the radical ion formation.     

A multivariate analysis of the IR spectra of tetrazole-containing copolymers

Copolymers of acrylic acid and 5-vinyltetrazole are studied by IR Fourier spectroscopy and by multivariate analysis of their IR spectra. It is found that the changes in the intensity of spectral peaks of the samples studied correlate with the conditions of obtaining of these copolymers.     

IR spectroscopic study of curing mechanism of epoxy oligomers by aluminum chelates

Conclusions The mechanism of the interaction of epoxy oligomers with aluminum chelates was studied by IR spectroscopy. It was found that the reaction proceeds between hydroxyl and epoxy groups, and alkoxy groups, and also between epoxy groups and the ligand, which leads to the formation of a tridimensional polymer.Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 4, pp. 607–611, April, 1990.     

Laser photochemical etching of silicon

Argon laser induced chemical etching of single crystal silicon with chlorine is studied. Etch rates are determined as a function of gas pressure, crystal orientation, laser power and wavelength. Analysis of gas phase and surface products by Fourier transform IR and X-ray photoelectron spectroscopy are used to probe the reaction mechanism. Contrary to previous reports, no thermally enhanced etch rate is observed for Si (111) and the presence of oxide on the surface is found to inhibit etching even at high laser power.     

Detecting molecular vibrational modes of side chains and endpoints in nanoscale proteins with graphene plasmon

Monitoring the chemical and structural changes in protein side chains and endpoints by infrared(IR)spectroscopy is important for studying the chemical reaction and physical adsorption process of proteins.However, the detection of side chains and endpoints in nanoscale proteins is still challenging due to its weak IR response. Here, by designing a double layered graphene plasmon sensor on MgF_2/Si substrate in the IR fingerprint region, we detect the vibrational modes in side chains and endpoints(1397 cm~(-1) and 1458 cm~(-1)) of monolayer protein. The sensor could be applied on biochemistry to investigate the physical and chemical reaction of biomolecules.     

二苄基锡炔基膦酸酯的红外光谱研究

研究了二苄基锡炔基膦酸酯的红外光谱，归属了这些化合物的特征红外吸收峰。     

生物酶活力的原位红外光谱测定

红外（IR）光谱近年来逐渐展示了它在生物医学领域中的应用,它不但能很好地用于体外酶催化活力分析和酶抑制剂的筛选,尤其可对活细胞进行原位酶活力测定和抑制剂筛选。IR光谱技术可用于生物酶活力的直接检的基本原理是基于单位时间内,反应物或者产物在IR光谱中特征吸收峰的峰位或强度的变化量来反映生物酶的催化效率。本文综述了利用IR光谱技术,对体外部分酶活力值进行分析和测定、以及对酶抑制剂的抑制效应进行评估和筛选;进而将该技术扩展至以活体细胞作为检测模型、开展细胞内生物酶活力值的测定及其抑制剂的筛选。同时,我们也对新近提出的在细胞原位测定酶活力的IR 方法及研究理念作了概述,生理条件下开展对生物酶活性无标记直接检测提供了新方法,并对该技术领域存在的问题及今后的发展趋势作出了展望。     

Diastereoselectivity and kinetics of hetero diels-alder reactions under high pressure

Abstract

The Hetero Diels-Alder reaction of enamino ketones and ethyl vinyl ether to give dihydropyrans is studied in different solutions under pressure up to 7 kbar. The kinetics is measured via on-line FT IR spectroscopy. The cycloaddition shows a remarkable pressure dependent increase in diastereo-selectivity. For the difference in activation volumes referring to the reaction to the two diastereomers, values up to 5.9 ± 0.5 cm³/mol are observed. The ratio of cis and trans diastereomers can be improved by almost one order of magnitude by changing pressure and temperature from 1 bar and 90 °C to 6 kbar and 0.5 °C.     

Pressure-induced dimerization kinetics of fullerene C60

Dimerization kinetics was studied for fullerene C₆₀ by IR spectroscopy at a pressure of 1.5 GPa in the temperature range 373–473 K. The kinetic curves for the formation of a dimer (C₆₀)₂ were obtained using its analytical IR band at 796 cm^?1. Under the assumption that pressure-induced C₆₀ dimerization is a second-order irreversible reaction, the reaction rate constants were determined at different temperatures. The corresponding activation energy and preexponential factor were found to be 134±6 kJ/mol and (1.74± 0.24)×10¹⁴ s^?1, respectively. The specific features of the solid-phase C₆₀ dimerization in simple cubic and face-centered cubic fullerite phases are discussed.     

Raman and IR studies of BaBi2Ta2O9 prepared by a sol–gel process

The formation of ferroelectric BaBi₂Ta₂O₉ (BBT) by a sol–gel process was studied by X‐ray, Raman and infrared (IR) spectroscopy. Our results show that the formation of a Bi‐layered phase proceeds via an intermediate fluorite‐type phase. This method allows obtaining a BBT phase already at 750 °C. This temperature is about 150–200 °C lower than that required in the conventional solid‐state reaction. Therefore, a material with smaller particle size can be obtained. Raman and IR studies of the obtained Bi‐layered phase show that phonon properties of the synthesized particles are slightly different from those of the bulk material due to the size effect, defects and weak changes in local order. Temperature dependence of Raman and IR wavenumbers is consistent with the orthorhombic distortion of the BBT structure. Copyright © 2011 John Wiley & Sons, Ltd.     

Study of lattice vibrational modes in CuGaS2 by using fourier transform spectroscopy

The lattice dynamics of a single crystal of CuGaS₂, grown by iodine transport technique, have been studied by using far IR absorption spectroscopy. All the absorption maxima caused by the phonon excitation are compared with the lattice vibrational modes obtained by Raman spectroscopy and by IR reflection techniques. An absorption maximum located at 175 cm^?1 cannot be explained with the help of phonon excitation; however this peak can be attributed to the defect frequency originating from the replacement of gallium atom by sulphur in the v₁₇ mode of vibration. The frequency of this defect-induced vibrational mode is calculated by taking a modified molecular model approach, and is found to be 166.9 cm^?1, which is in reasonably good agreement with the experimentally observed value of 175 cm^?1.     

微囊藻毒素-LR的特征红外光谱

利用傅里叶变换红外(FTIR)光谱仪研究了微囊藻毒素-LR在扫描范围4 000～600 cm-1的红外吸收光谱图,微囊藻毒素-LR分子构成中的主要官能团,如带有单一取代基的苯环、胍基、γ-羧基等特征红外吸收带在谱图上均得到了确认。