1-氯-2,2,2-三氟乙基二氟甲基醚红外光谱研究

1-氯-2,2,2-三氟乙基二氟甲基醚(以下简称异氟醚)是一类重要的吸入性麻醉剂。采用3种中红外(MIR)光谱(透射中红外(T-MIR)光谱、衰减全反射中红外(ATR-MIR)光谱、漫反射中红外(DR-MIR)光谱)和4种MIR光谱(一维MIR光谱、二阶导数MIR光谱、四阶导数MIR光谱、去卷积MIR光谱)计算方法开展了异氟醚的分子结构研究。试验发现:异氟醚的红外吸收模式主要包括异氟醚分子CF_2不对称伸缩振动模式(ν_(asCF_2-异氟醚))、异氟醚分子CF_2对称伸缩振动模式(ν_(sCF_2-异氟醚))、异氟醚分子CF_3不对称伸缩振动模式(ν_(asCF_3-异氟醚))和异氟醚分子CF_3对称伸缩振动模式(ν_(sCF_3-异氟醚))等。试验同时发现:3种MIR光谱中,异氟醚DR-MIR光谱质量要优于相应的ATR-MIR光谱和T-MIR光谱;而4种MIR光谱的计算方法中,异氟醚去卷积MIR光谱的谱图质量要优于相应的一维MIR光谱、二阶导数MIR光谱和四阶导数MIR光谱。研究拓展了MIR光谱在重要的氟烃类化合物(异氟醚)结构研究中的应用范围。     

聚乙烯C–H伸缩振动二维红外光谱研究

在293~393 K范围内,分别测定聚乙烯(PE)的一维红外光谱、二阶导数红外光谱和去卷积红外光谱来确定PE分子结构。进一步采用二维红外光谱研究了聚乙烯亚甲基C–H伸缩振动模式(νCH2)的模式。研究发现,PE分子中存在晶区和非晶区。随着测定温度的升高,PE分子中νCH2红外吸收强度变化快慢顺序为:2 920 cm-1(νas(CH2)crystalline)2 930 cm-1(νas(CH2)amorphous)2 850 cm-1(νs(CH2)crystalline)2 858 cm-1(νs(CH2)amorphous)。此项研究显示出二维红外光谱在高分子材料热变性分析中的重大作用。     

氟烷红外光谱的研究

采用红外(IR)光谱法,对氟烷(包括七氟烷、恩氟烷和异氟烷)进行分子结构研究。试验发现:氟烷的红外吸收模式主要有CF_3不对称伸缩振动模式(ν_(asCF_3-氟烷))、CF_3对称伸缩振动模式(ν_(sCF_3-氟烷))、CF_2不对称伸缩振动模式(ν_(asCF_2-氟烷))、CF_2对称伸缩振动模式(ν_(sCF_2-氟烷))和CF伸缩振动模式(ν_(CF-氟烷))等。结合氟烷的核磁共振氟谱(~(19)F-NMR)进一步研究了不同取代基团对于氟烷分子诱导效应的影响。此研究拓展了IR光谱在氟烷结构的应用研究范围。     

Parafilm的红外光谱研究

采用变温红外光谱技术,分别研究了封口膜(Parafilm)的一维变温红外光谱和二阶导数变温红外光谱。结果表明:Parafilm主要存在CH_3的不对称伸缩振动模式、CH_2的不对称伸缩振动模式、CH_2的对称伸缩振动模式、CH_2的变角振动模式、CH_3的不对称变角振动模式、CH_3的对称变角振动模式、C—C骨架的伸缩振动模式和CH_2的面内摇摆振动模式等8种红外吸收模式;最终确定Parafilm的主要结构是聚异丁烯,而其临界相变温度为313 K。以Parafilm的CH_2面内摇摆振动模式为研究对象,进一步开展相关二维红外光谱研究。     

六氟异丙醇-水溶液中红外光谱研究

采用中红外(MIR)光谱技术,包括一维MIR光谱、二阶导数MIR光谱、四阶导数MIR光谱和去卷积MIR光谱分别开展六氟异丙醇分子结构的研究。试验发现,六氟异丙醇分子的主要红外吸收官能团包括ν_(asCF_3-六氟异丙醇)、ν_(sCF_3-六氟异丙醇)、ν_(CO-六氟异丙醇)和δ_(asCF_3-六氟异丙醇)等。采用一维MIR光谱开展了六氟异丙醇-水溶液结构的研究,研究发现,随着六氟异丙醇浓度降低,六氟异丙醇-水溶液分子间的氢键作用逐步减弱。并进一步进行了相关机理研究,为六氟异丙醇-水溶液的结构研究建立了一个新的方法学,具有重要的应用研究价值。     

聚氯乙烯亚甲基弯曲振动ATR二维红外光谱研究

在303~393 K的温度范围内,利用变温傅里叶变换衰减全反射红外光谱(ATR-FTIR),分别研究了聚氯乙烯亚甲基弯曲振动模式δ_(CH_2)的一维红外光谱、二阶导数红外光谱、四阶导数红外光谱、去卷积红外光谱和二维红外光谱。结果表明:当温度低于玻璃化转变温度时,聚氯乙烯分别在1420、1425、1430、1435和1447 cm~(-1)处出现红外吸收峰,随着温度的升高,聚氯乙烯δCH_2红外吸收强度的变化快慢顺序为1447 cm~(-1)1420 cm~(-1)1430cm~(-1)1425 cm~(-1)1435 cm~(-1);当温度超过玻璃化转变温度后,聚氯乙烯在1420、1425、1430和1435 cm~(-1)处出现红外吸收峰,而随着温度的升高,聚氯乙烯δCH_2红外吸收强度的变化快慢顺序为1425 cm~(-1)1420 cm~(-1)1430 cm~(-1)1435 cm~(-1)。此项研究拓展了ATR-FTIR技术在聚氯乙烯热变性方面的应用范围。     

聚四氟乙烯三级中红外光谱研究

采用中红外(MIR)光谱(包括:一维MIR光谱和二阶导数MIR光谱)研究了聚四氟乙烯(PTFE)的分子结构。研究发现:PTFE的MIR吸收模式主要包括:F—C—F弯曲振动模式(δ_(CF_2-PTFE))和F—C—F伸缩振动模式(ν_(CF_2-PTFE))。进一步开展了PTFE的变温中红外(TD-MIR)光谱研究。研究发现:随着测定温度的升高,PTFE的δ_(CF_2-PTFE)和ν_(CF_2-PTFE)对应的红外吸收频率及强度均有明显的改变。以PTFE玻璃化温度(T_g)为临界温度,采用二维中红外(2D-MIR)光谱,进一步开展了PTFE热稳定性的研究。研究发现:在303～393 K和403～523 K二个温度区间,PTFE主要官能团δ_(CF_2-PTFE)和ν_(CF_2-PTFE)热敏感程度及变化顺序都存在着较大的差异性,并进一步进行了机理的研究。本项研究拓展了三级MIR光谱(包括:MIR光谱、TD-MIR光谱和2D-MIR光谱)在重要的有机氟高分子材料PTFE结构及热稳定性的研究范围。     

东阿阿胶红外光谱研究

采用傅里叶变换衰减全反射红外光谱技术(ATR-FTIR),分别研究了东阿阿胶和伪品东阿阿胶的红外光谱。实验发现:东阿阿胶和伪品东阿阿胶同时存在着CH_3不对称伸缩振动模式(ν_(asCH3)),CH_2不对称伸缩振动模式(ν_(asCH2)),CH_2对称伸缩振动模式(ν_(sCH2)),酰胺Ⅰ带对应的红外吸收模式(νamide-Ⅰ),酰胺Ⅱ带对应的红外吸收模式(νamide-Ⅱ)和酰胺Ⅲ带对应的红外吸收模式(νamide-Ⅲ)。研究发现,采用红外光谱技术可以区分东阿阿胶和伪品东阿阿胶。本项研究拓展了红外光谱技术在中药鉴别领域的研究范围。     

聚对苯二甲酸乙二醇酯反式及左右式构象互变机理研究

采用红外光谱(IR光谱)研究了聚对苯二甲酸乙二醇酯(PET)分子结构。PET亚甲基变角振动模式(δCH2)主要包括:PET亚甲基左右式变角振动模式(δCH2-左右式)和PET亚甲基反式变角振动模式(δCH2-反式)。以PET/δCH2-左右式和PET/δCH2-反式为研究对象,进行了变温红外光谱(TD-IR光谱)研究。实验发现:随着测定温度的升高,PET/δCH2-左右式和PET/δCH2-反式对应的红外吸收频率及强度均有明显的改变,而玻璃化温度(Tg)是一个临界温度。采用二维红外光谱(2D-IR谱),进一步开展了PET反式及左右式构象互变机理研究。拓展了三级IR光谱(包括:IR光谱、TD-IR光谱和2D-IR光谱)在重要的高分子材料(PET)结构及构象转变的研究范围。     

聚丙烯变温傅里叶变换透射红外光谱研究

采用变温傅里叶变换透射红外光谱技术,研究了聚丙烯的分子结构。实验发现:聚丙烯主要存在CH_3不对称伸缩振动模式(ν_(asCH_3))、CH_3对称伸缩振动模式(ν_(asCH_3))、CH_2不对称伸缩振动模式(ν_(asCH_2))、CH_2对称伸缩振动模式(ν_(sCH_2))、CH_3不对称弯曲振动模式(δ_(asCH_3))、CH_3对称弯曲振动模式(δ_(sCH_3))、CH_2弯曲振动模式(δ_(CH_2))和聚丙烯结晶振动模式(δ crystalline)等。采用变温傅里叶变换透射红外光谱技术进一步研究了温度变化对于聚丙烯分子结构的影响。研究发现,在293~393K温度范围内,聚丙烯分子具有良好的热稳定性。本项研究拓展了变温傅里叶变换透射红外光谱技术在聚丙烯材料热变性方面的研究范围。     

碳酸钙三级红外光谱研究

采用红外（IR）光谱技术开展了碳酸钙的结构研究。实验发现,碳酸钙的红外吸收模式包括碳酸钙CO₃不对称伸缩振动模式（ν）、碳酸钙 CO₃对称伸缩振动模式（ν）、碳酸钙CO₃面外弯曲振动模式（r）和碳酸钙CO₃面内弯曲振动模式（β）等。采用变温红外（TD-IR）光谱开展了碳酸钙的热稳定性研究。在293~393 K的温度范围内,碳酸钙主要官能团对应的吸收强度及频率都有一定的改变。采用二维红外（2D-IR）光谱进一步研究了碳酸钙ν、r和β吸收峰变化快慢的信息,证明了三级红外（IR）光谱在重要的无机盐（碳酸钙）结构及热稳定性研究中的重要作用。     

噻唑电子激发和光解动力学研究

获得了噻唑的共振拉曼光谱,结果表明,在Franck Condon区域,噻唑的激发态结构动力学主要由9个活性振动模组成。不对称C-S伸缩振动模ν12的出现,表明在S1态时噻唑两个C-S键发生了不同程度键长变化,一个显著伸长,另一个却变化不大。预示噻唑可能在S1态时与某个非绝热单重态Sn存在锥形交叉,导致噻唑发生C-S键断裂而解离。     

Near‐infrared spectra of polyamide 6, poly(vinyl chloride), and polychlorotrifluoroethylene

The near‐infrared spectra (NIR) of polyamide 6 (PA 6), poly(vinyl chloride) (PVC), and polychlorotrifluoroethylene (PCTFE) were measured. The tentative assignment of the overtone and combination frequencies was made with curve fitting calculations and local mode theory. Anharmonicity correction and mechanical frequency were determined from a Birge–Sponer plot. Tentative assignments of stretch overtone frequencies of CH₂, NH, and CO functional groups of PA 6 and CH₂, and CH functional groups of PVC were made. Anharmonicity corrections of 55, 61, and 20 cm^?1 were obtained for CH₂, NH, and CO stretch modes of PA 6, respectively, and of 60 and 66 cm^?1 for CH₂ and CH stretch modes of PVC, respectively. The local mode model seems to be adequate to interpret the origin of the bands observed in NIR spectra of PA 6 and PVC. Anharmonicity corrections of 33, 19, and 16 cm^?1 were obtained, respectively, for CF, asymmetrical CF₂, and symmetrical CF₂ stretch of PCTFE functional groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 199–208, 2002     

原位红外研究噻吩在硫化后Co-Mo/γ-Al2O3催化剂上吸附行为

在原油质量下降的趋势和柴油硫含量标准不断提升的背景下，为提升加氢脱硫催化剂催化活性及改进清洁油品的生产工艺，本文采用原位红外技术研究工业用直接脱硫路径活性较高的Co-Mo/γ-Al₂O₃催化剂的硫化行为和噻吩的吸附行为。实验结果表明，Co-Mo/γ-Al₂O₃催化剂的表面在约320℃硫化，噻吩在硫化后的Co-Mo/γ-Al₂O₃催化剂上原位升温脱附的过程中，噻吩的CC伸缩振动峰（1558cm^-1）和CH面内弯曲振动峰（1413cm^-1）在约250℃消失（对应π络合吸附）；CC伸缩振动峰（1679、1575cm^-1）和CH面内弯曲振动峰（1396cm^-1）在约350℃消失（对应M-S吸附）；而CC伸缩振动峰（1537、1513cm^-1）和CH面内弯曲振动峰（1338cm^-1）持续增强（对应π络合吸附）。这明晰了噻吩的吸附方式与其脱附温度之间的关系，为新型加氢脱硫催化剂的设计开发提供了试验数据支持。     

Characterization of ethylene in EP and in iPP/EP systems by deconvolution of IR spectra

The purpose of this study is to propose a correlation between IR spectra and molecular structure of ethylene‐propylene (EP) copolymers possibly blended with isotactic polypropylene (iPP). The method is based on the deconvolution of the spectrum in the CH₂‐rocking range, i.e., 800–680 cm⁻¹, where the bands of interest overlap. The six bands present in this region were signal averaged in position and width. The spectra were then deconvoluted (curve fitted) assuming a Lorentzian shape for the bands. The band at 1167 cm⁻¹ (with a shoulder at 1156 cm⁻¹) corresponding to a CH₃ vibration is considered as an internal standard. The method was checked by varying some fitting parameters. In order to realize some quantitative measurements, calibration curves were established with some EP samples, characterized by ¹³C NMR, which were used as standards. The amounts of total  (CH₂ CH₂) units (ethylene units), isolated ethylene and structural defaults in PP were determined for different iPP/EP blends. Ethylene crystallinity has also been determined. A good correlation was evidenced between infrared and ¹³C NMR measurements. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 96–106, 2000     

A DFT Study of Vibrational Spectra and Mutagenicity Predictions of Mononitrated Fluoranthenes

The Raman and infrared (IR) spectra of the mononitrated fluoranthenes (1-, 2-, 3-, 7-, and 8-nitrofluoranthene), important environmental pollutants that induce mutagenic/carcinogenic effects upon mammalian and bacterial cells, were studied via density functional theory, using optimized geometries at the B3LYP/6-311+G(d,p) and PBE0/6-311+G(d,p) levels of theory. The predicted harmonic vibrational frequencies were used in normal mode assignments. To validate the spectra, experimental fluoranthene and 3-nitrofluoranthene were used to benchmark the predicted spectra. The scaled harmonic frequencies below 2000 cm^?1are in good agreement to experiment to <5 cm^?1and 10 cm^?1or better at the B3LYP/6-311+G(d,p) and PBE0/6-311+G(d,p) levels, respectively. The high intensity nitro asymmetric/symmetric stretch modes (ν_asym/ν_symNO₂), ν(C?C) and ν(C?H) stretch frequencies were then considered, and used in distinguishing nitrofluoranthene isomers. The ν_sym(NO₂) frequency shifts are correlated to the observed mutagenic potencies, thus shedding light on their relative reactivity. The observed differential mutagenic-vibrational correlations, and implications of the ν_NO2shifts/biological mutagenic potencies between nitrofluoranthene isomers are then discussed.

Supplemental materials are available for this article. Go to the publisher's online edition of Polycyclic Aromatic Compounds to view the supplemental file.     

Effect of solvent on structure and optical properties of PZT nanoparticles prepared by sol-gel method, in infrared region

Single-phase perovskite Pb(Zr_0.52,Ti_0.48) nanoparticles, PZT-NPs were prepared by the sol-gel method with two different solvents, 2-methoxyethanol, EGME, and poly ethylene glycol, PEG. X-ray diffraction (XRD) was used to study of the structure of the PZT-NPs. Fourier transform infrared spectroscopy (FTIR) was used to measure the infrared reflectivity spectrum in the range of 4000-280 cm⁻¹. Infrared active vibration modes of BO₆ octahedral (ν₁ and ν₂) were observed for PZT-NPs below 600 cm⁻¹. The third vibration mode of Pb against the TiO₃ group, ν₃, occurred below the experimentally accessible range. The Kramers-Kronig method (K-K) and classical dispersion theory were applied to analyze the data and calculation of the optical constants such as reflective index (N(ω))and permittivity (?(ω)). The results showed that the structure and optical properties of PZT-NPs were changed by different type of solvent.     

不同产地、不同种属黄精的红外光谱鉴别研究

采用傅里叶红外光谱技术结合二阶导数光谱对不同产地的黄精进行鉴别。研究结果表明,不同产地多花黄精的红外光谱图在整体上比较相似,其主要吸收峰均在3270、2933、1623、1411、1372、1319、1269、1103、1019、926、865、815 cm-1附近,但吸收峰的位置、峰强度等方面存在明显差异,在1018 cm-1附近是糖类的特征吸收峰,由红外光谱图可推测安徽省池州市、岳西县、江西省宜春市多花黄精中糖类成分含量较高,湖北省黄冈市、安徽省黄山区、石台县次之,安徽省休宁县、金寨县相对较少。6种黄精属植物的红外光谱图在吸收峰的位置、形状、强度等方面均有差异,故可推测黄精属不同植物在化学成分及含量上均存在明显差异。二阶导数图呈现出许多原始图谱中被掩盖的谱峰的变化特征,将谱图间的差异更为明显得表现出来,进一步提高了谱图的分辨率,与普通红外光谱图相比,二阶导数红外光谱图进一步直观地验证了上述结果。     

Effect of ground fluororubber vulcanizate powder on the properties of fluororubber compound

Fluororubber vulcanizate powder (FVP) obtained from fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer by mechanical grinding exists in a highly aggregated chain‐like structure. X‐ray photoelectron spectros‐copy (XPS) and infrared (IR) spectroscopy studies show that there are no chemical change on the rubber surface following mechanical grinding of the fluororubber vulcanizate after heat aging at 200°C for 10 days. The incorporation of FVP as a filler in the fluororubber compound results in a marginal increase of Mooney viscosity, Mooney scorch time and shear viscosity. While tensile strength, modulus and hardness marginally increase on addition of FVP into the fluororubber compound, tear strength decreases. Rhemetric studies show that FVP alone is susceptible to further crosslinking in the presence of a curing agent. Dynamic mechanical spectra reveal that the glass to rubber transition temperature shifts higher by the addition of FVP into the fluororubber compounds. Atomic force microscopy (AFM) images show uniform dispersion of FVP particles into the rubber matrix.