High-resolution IR Research Articles

Vibrational assignment of isoxazole aided by rovibrational data and density functional theory

IR and Raman spectra of isoxazole and D 3-isoxazole are reassigned with the aid of density functional theory calculations at the B3LYP/6-311+G(d,p) level. Harmonic wavenumber values of all non-CH stretch modes give an r.m.s. deviation from experimental values of 3 cm −1 when they are uniformly scaled by 0.9818. Anharmonic values obtained using a second-order perturbative approach show an r.m.s. deviation of 7.6 cm −1. Results of equal quality are obtained for D 3-isoxazole. Predicted Raman and IR band strengths match experimental spectra very closely. Detailed re-examination of rovibrational constants and inertial defect data from high resolution IR spectra, in comparison with values from the anharmonic frequency calculation, provides confirmation of the vibrational assignments. ‘Dark state’ fundamentals ν 12 (900.2 cm −1) and ν 15 (866 cm −1) are detected through the perturbations they cause in nearby bands.

High-resolution absorption cross-section of glyoxal in the UV–vis and IR spectral ranges

High-resolution absorption cross-sections of glyoxal have been recorded at 296 K in the ultraviolet and visible (UV–vis: 19000–40000 cm −1, 250–526 nm) and infrared (IR: 1200–8000 cm −1) spectral ranges by means of a Fourier transform spectrometer (FTS). The UV–vis spectra were measured at 1 atm of N 2 bath gas. The spectral resolution of the FTS was selected to be 0.06 cm −1 for the richly structured A ˜ 1A u – X ˜ 1A g and a ˜ 3A u – X ˜ 1A g band systems, and 1 cm −1 for the diffuse B ˜ − X ˜ transition, which was sufficient to resolve most spectral structures. In addition, low and high-resolution IR spectra (1 and 0.009 cm −1 spectral resolution) of glyoxal/N 2 mixtures were recorded around 2835 cm −1 at 0.2 mbar, 100 mbar, 300 mbar and 1 atm total pressure. UV–vis and IR spectra were recorded quasi-simultaneously by making sequential measurements of identical glyoxal mixtures in the cell, enabling the direct comparison of UV–vis and IR spectral parameters for the first time. The high-resolution spectra have been used to simulate deviations from Lambert–Beer's law, which occur at lower resolution when spectra are not fully resolved. Special attention has been paid to reduce the uncertainty of the UV–vis spectrum, allowing for an improved determination of the atmospheric photolysis of glyoxal. Finally, the new UV–vis spectrum has been used to redetermine our previous DOAS measurements of glyoxal yields from the reactions of OH radicals with benzene, toluene and p-xylene. The high-resolution spectral data can be obtained from http://iup.physik.uni-bremen.de/gruppen/molspec/index.html or email request to the authors.

Intramolecular energy transfer between oriented chromophores: High-resolution infrared spectroscopy of HCl trimer

Detailed dynamical and structural information has been obtained for hydrogen-bonded (HCl)(3) clusters via high-resolution IR laser absorption spectroscopy in a supersonic slit expansion. Multiple rovibrational bands in an approximately 3000 cm(-1) HCl stretch region have been assigned and analyzed for H (35)Cl/H (37)Cl isotopomeric contributions, corresponding to excitation of (i) the degenerate antisymmetric HCl stretch in isotopically pure (H (35)Cl)(3), (ii) high- and low-frequency components of the nearly degenerate HCl stretch in H (37)Cl (H (35)Cl)(2), (iii) the low-frequency component of the corresponding HCl stretch in (H (37)Cl)(2) H (35)Cl. The isotopically pure (H (35)Cl)(3) results are in good agreement with earlier diode-laser efforts. A simple exciton model for vibrational coupling between HCl subunits is presented that indicates rapid intramolecular energy flow (beta approximately -1.89 cm(-1), tau approximately 2.8 ps) in the trimer ring, which is in good agreement with vibrationally mediated tunneling rates observed in the HCl dimer. Spectral analysis at slit jet resolution indicates a Deltanu approximately 120 MHz homogeneous line broadening and an excited-state lifetime of approximately 1.3 ns. The data is consistent with intramolecular vibrational redistribution-induced opening of the trimer followed by true predissociation to either (HCl)(2)+HCl or 3HCl on a longer time scale.

Analysis of improvement amount of typical microscanning modes to IR imagery quality

Microscanning is an important technique in high-resolution IR imaging field. It can increase the system resolution and improve the performance of imaging systems. For the optimum design of IR staring imaging system with microscanning modes, it is necessary to study the effect of different microscanning modes on the image quality. Three types of microscanning modes generally used, 2×2, 3×3, 4×4, are analyzed in this paper. Under some assumptions, this paper introduces sampling-averaging MTF of detector array at spatial Nyquist frequency to quantitatively study the improvement of different microscanning modes to image quality. Finally, image histogram analysis method is used to discuss qualitatively the effect of microscanning modes on the image quality. Simulation experimental results show a good agreement with theoretical analysis.

Thelephantins I—N: p‐Terphenyl Derivatives from the Inedible Mushroom Hydnellum caeruleum.

Phytochemical investigation of the methanolic extract of the fruiting bodies of the inedible mushroom Hydnellum caeruleum resulted in the isolation of six p-terphenyl derivatives named thelephantins I-N (1-6), together with a known compound, dihydroaurantiacin dibenzoate (7). These structures were determined by high-resolution MS, 2D NMR, IR and UV spectroscopic analysis, and by the chemical reactions.

Novel Naphthoquinones from Heterophragma adenophyllum.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Spectroscopic and dynamic studies of the photolysis reaction of acetone by 193 nm excimer laser

The high-resolution time resolved Fourier transformed IR spectroscopy is used here to measure the emitted spectra of the CO fragment resulting from the photolysis of acetone by 193nm excimer laser. A high-resolution IR spectra in the range of 1950–2250cm−1, is assigned to be CO ro-vibrational transition. The vibrational population of the first four vibrational levels were obtained by simulating of these spectra. The vibrational temperature TVib. of the CO was found to be 2250±70K as given from the Boltzmann plot. Moreover, the Boltzmann distribution was found to fit the rotational degrees of freedom yielding a characteristic temperature TRot. of the CO of about 2250K in the case of low relaxation and 1μs time delay experiment. The prior distribution model was found to predict the vibrational and rotational energies lower than the measured values. While the impulsive model predicts higher values, the statistical adiabatic model used here was found to predict values for ET, EVib., ERot. according well with the measured experimental values.

Novel Naphthoquinones from Heterophragma adenophyllum

AbstractA new symmetric naphthoquinone dimer, dilapachone (1), and a novel asymmetric naphthoquinone dimer, adenophyllone (2), were isolated from the heartwood of Heterophragma adenophyllum. Their structures were elucidated by spectroscopic means including high‐resolution mass, UV, IR, 1D‐ and 2D‐NMR spectroscopy.

Thelephantins I–N: p-terphenyl derivatives from the inedible mushroom Hydnellum caeruleum

Phytochemical investigation of the methanolic extract of the fruiting bodies of the inedible mushroom Hydnellum caeruleum resulted in the isolation of six p-terphenyl derivatives named thelephantins I–N ( 1– 6), together with a known compound, dihydroaurantiacin dibenzoate ( 7). These structures were determined by high-resolution MS, 2D NMR, IR and UV spectroscopic analysis, and by the chemical reactions.

Thelephantins D—H: Five p‐Terphenyl Derivatives from the Inedible Mushroom Thelephora aurantiotincta.

ChemInformVolume 34, Issue 49 Natural Products Thelephantins D—H: Five p-Terphenyl Derivatives from the Inedible Mushroom Thelephora aurantiotincta. Dang Ngoc Quang, Dang Ngoc Quang Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorToshihiro Hashimoto, Toshihiro Hashimoto Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorYuki Hitaka, Yuki Hitaka Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorMasami Tanaka, Masami Tanaka Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorMakiko Nukada, Makiko Nukada Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorIsao Yamamoto, Isao Yamamoto Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorYoshinori Asakawa, Yoshinori Asakawa Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this author Dang Ngoc Quang, Dang Ngoc Quang Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorToshihiro Hashimoto, Toshihiro Hashimoto Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorYuki Hitaka, Yuki Hitaka Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorMasami Tanaka, Masami Tanaka Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorMakiko Nukada, Makiko Nukada Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorIsao Yamamoto, Isao Yamamoto Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this authorYoshinori Asakawa, Yoshinori Asakawa Fac. Pharm. Sci., Tokushima Bunri Univ., Yamashiro, Tokushima 770, JapanSearch for more papers by this author First published: 11 November 2003 https://doi.org/10.1002/chin.200349210Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume34, Issue49December 9, 2003 RelatedInformation

Thelephantins D–H: five p-terphenyl derivatives from the inedible mushroom Thelephora aurantiotincta

Five p-terphenyl derivatives named thelephantins D–H ( 1– 5) together with nine known compounds, thelephantins A–C ( 6– 8), ganbajunin E ( 9), p-hydroxylbenzoic acid ( 10), ganbajunin C ( 11), thelephorin A ( 12), 2- O-methylatromentin ( 13) and atromentin ( 14), were isolated from the methanolic extract of fruit bodies of the Thelephoraceous Basidiomycete Thelephora aurantiotincta. Their structures were elucidated by high-resolution MS, 2D NMR, IR and UV spectroscopic analysis.

Wavelength calibration of spectra measured by the Global Ozone Monitoring Experiment by use of a high-resolution reference spectrum.

Earthshine spectra measured by the nadir-viewing Global Ozone Monitoring Experiment (GOME) spectrometer aboard the second European Remote Sensing (ERS-2) Satellite in the range of 240-790 nm are widely used for the retrieval of concentrations and vertical profiles of atmospheric trace gases. For the near-real-time delivery of ozone columns and profiles at the Royal Netherlands Meterological Institute, a tailor-made wavelength calibration method was developed. The method use a high-resolution (0.01-nm) solar spectrum as the reference spectrum and applies both a shift and a squeeze to the wavelengths in selected windows to find the optimal wavelength grid per window. This method provides a calibration accuracy of 0.002 nm below and 0.001 nm above 290 nm. The new wavelength calibration method can be used on any wavelength window, for example, to improve the calibration of spectra from the GOME Data Processor. A software package, GomeCal, which performs this recalibration, along with an improved polarization and radiometric correction, has been made and has been released via the World Wide Web. The method can be used for any high-resolution (ir)radiance spectrometer, such as the satellite instruments SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Cartography), Ozone Monitoring Instrument, and GOME-2.

High-resolution IR spectroscopy of a high lying K a = 0 mode of the weakly bound van der Waals complex Ar—CO

The infrared spectrum of the weakly bound van der Waals complex Ar-CO has been studied in the 2174cm−1 region using a lead salt diode laser spectrometer. We assigned the observed lines to a K a = 0 ← 0 subband. The upper state corresponds to the highest known van der Waals mode of this prototype complex which has been detected so far.

Controlling Particle Morphology during Growth of Bayerite in Aluminate Solutions

To study the influence of the orientations of the faces of metal oxyhydroxides on their surface reactivity, the synthesis of bayerite [β-Al(OH)3] particles with different morphologies was studied. The growth of bayerite was performed in aqueous solution at 70 °C by continuously injecting a sodium aluminate solution and stabilizing the pH at a constant value by monitoring the injection of a nitric acid solution. The effects of the following parameters were studied: pH, flow rate of aluminate solution, total duration of synthesis, and seeding. The solids were characterized by high-resolution SEM, XRD, IR spectroscopy, thermogravimetric analysis, and surface area measurements. By choosing the growth parameters, we were able to control the morphology of particles with shapes ranging from agglomerates of rods or cones to ovoid crystallites. In certain cases, traces of gibbsite, norstandite, and pseudoboehmite were obtained in addition to bayerite, but their quantity can be minimized.

Isolation and identification of an allelopathic substance in Pisum sativum

The residue of peas ( Pisum sativum L.) has allelopathic activity and the putative compound causing this inhibitory effect was isolated from a methanol extract of pea shoots. Chemical structure of this compound was determined by high-resolution MS, IR and 1H NMR spectral data as pisatin. Pisatin inhibited growth of cress ( Lepidium sativum L.) and lettuce ( Lactuca sativa L.) seedlings at concentrations greater than 10 and 30 μM, respectively. The doses required for 50% growth inhibition of roots and hypocotyls of cress were 61 and 91 μM, respectively, and those of lettuce were 78 and 115 μM, respectively. The concentration of pisatin in the pea shoots was 32.7 nmol g −1 fresh weight. The effectiveness of pisatin on growth inhibition in cress and lettuce, and its occurrence in pea shoots suggest that it may contribute to the growth inhibitory effect of pea residue, and may play an important role in pea allelopathy.

A new iron oxophosphate SrFe 3(PO 4) 3O with chain-like structure

A new strontium iron oxophosphate SrFe 3(PO 4) 3O was synthesized by the solid state method and its structure was studied by single-crystal X-ray and electron diffraction, high-resolution electron microscopy, Mössbauer and IR spectroscopy. The compound crystallizes in a monoclinic system (space group P2 1 /m) with unit-cell parameters: a = 7.5395(7), b = 6.3476(7) c = 10.3161(13) Å, β = 99.740(9)°. The structure of SrFe 3(PO 4) 3O represents a new structural type and is made up of isolated PO 4 tetrahedra and FeO n polyhedra connected via common vertices and edges to form a 3D framework. Iron cations occupy three crystallographically independent sites with different oxygen environment: Fe1 and Fe2 occupy two octahedral sites, and Fe3 is five-coordinated. Two particularities of this structure are remarkably mentioned: the isolated {FeO 6} n octahedral chains along the b direction and the five coordinated environment for the Fe3 position. Mössbauer spectroscopy confirmed the presence of only high-spin Fe 3+ cations in two types of coordination environment. The IR-data show the presence of only PO 4 3− groups.

Reading between the lines: Exposing underlying features of high resolution infrared spectra (CHClF2)

A technique to facilitate the assignment of congested high resolution IR spectra is presented. It involves subtraction of component spectra simulated from known spectroscopic constants. Application to the ν2 (1313.1 cm−1) and ν7 (1351.7 cm−1) bands of CHClF2 led to rovibrational line assignments for less intense and overlapping features including the minor isotopomer CH37ClF2 and c-type lines of CH35ClF2. The number of transitions assigned to the fundamental bands increased from 1721 to 6031 for 37Cl, and from 7496 to 9664 for 35Cl, with a greater range of rotational quantum numbers than found in a previous study. A total number of 1457, 484 and 262 line assignments were made for 210911, 710911 and 210611 hotbands respectively, features otherwise completely obscured in the observed spectrum. Rotational and centrifugal distortion parameters were fitted for all the upper states.

IR-High resolution spectroscopy of the N2O dimer: The torsional modeElectronic supplementary information (ESI) available: List of measured rotational transitions and assignments. See http://www.rsc.org/suppdata/cp/b3/b300733m/

Download options Please wait... Supplementary files Measured infrared transitions and their assignments. PDF (76K) Article information DOI https://doi.org/10.1039/B300733M Article type Paper Submitted 17 Jan 2003 Accepted 27 Mar 2003 First published 29 Apr 2003 Download Citation Phys. Chem. Chem. Phys., 2003,5, 2333-2336 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions IR-High resolution spectroscopy of the N2O dimer: The torsional mode A. Hecker, I. Scheele and M. Havenith, Phys. Chem. Chem. Phys., 2003, 5, 2333 DOI: 10.1039/B300733M To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author A. Hecker I. Scheele M. Havenith

Thelephantins A, B and C: three benzoyl p-terphenyl derivatives from the inedible mushroom Thelephora aurantiotincta

Three benzoyl p-terphenyl derivatives named thelephantins A, B and C were isolated from the ethyl acetate extract of fruit bodies of the Thelephoraceous Basidiomycete Thelephora aurantiotincta. Their structures were elucidated by analysis of high-resolution 2D NMR, MS, IR and UV spectra.

A new method for the quantitative identification of the composition, size and density of stratospheric aerosols from high resolution IR satellite measurements

We describe a new method for the rapid and quantitative determination of the composition, size and density of atmospheric aerosols from broadband high resolution IR spectra recorded by remote sensing instruments. This method uses a novel technique for the separation of the aerosol spectrum from that of the gas phase. It is fast enough to permit the analysis of high resolution IR satellite measurements in real time, yielding aerosol composition, size distribution and volume density. The method is applied to spectra measured by the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument during flights in March 1992, shortly after the eruption of Mount Pinatubo, and again in November 1994. We report the chemical and physical characteristics of the stratospheric aerosols as a function of the tangent height.