6.2.2. Definition of Effective Properties 3064 6.3. Response Properties to Magnetic Fields 3066 6.3.1. Nuclear Shielding 3066 6.3.2. Indirect Spin−Spin Coupling 3067 6.3.3. EPR Parameters 3068 6.4. Properties of Chiral Systems 3069 6.4.1. Electronic Circular Dichroism (ECD) 3069 6.4.2. Optical Rotation (OR) 3069 6.4.3. VCD and VROA 3070 7. Continuum and Discrete Models 3071 7.1. Continuum Methods within MD and MC Simulations 3072

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Quantum mechanical continuum solvation models.

This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.

/pdf/the-hitran-2008-molecular-spectroscopic-database-1ud8clpej3.pdf

The HITRAN 2008 molecular spectroscopic database

Jenny Schneider,*,† Masaya Matsuoka,‡ Masato Takeuchi,‡ Jinlong Zhang, Yu Horiuchi,‡ Masakazu Anpo,‡ and Detlef W. Bahnemann*,† †Institut fur Technische Chemie, Leibniz Universitaẗ Hannover, Callinstrasse 3, D-30167 Hannover, Germany ‡Faculty of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China

Understanding TiO2 photocatalysis: mechanisms and materials.

In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag+ (in the form of AgNO3). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.

http://www.omnis-mg.hr/Radovi/EC-oblik-koreja.pdf

Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the Gram-negative bacterium Escherichia coli.

Infrared spectroscopy of proteins.

Interfaces between chromatographs and FT-IR spectrometers based on mobile phase elimination and eluite deposition are usually more sensitive than flow cell methods. In the GC/FT-IR 1,2 and SFC/FT-IR314 interfaces developed by our group, the eluites are deposited in a small area (<0.04 mm2) on a moving infrared transparent window (usually ZnSe) and their spectra are measured using an FT-IR microscope. One advantage that has been ascribed to this technique is the ability to use standard condensed phase spectral libraries for spectral searching.5 In this paper, the results of a systematic study are described in which SFC/FT-IR spectra are compared to libraries of condensed phase reference spectra. The particular analytes that were investigated were chosen to probe several possible sources of variation between SFC/FT-IR spectra and reference spectra of the same compounds prepared as KBr disks.

Advantages And Disadvantages Of A Chromatographic/FT-IR Interface Based On Mobile Phase Elimination

Materials used in the manufacture of silicone breast prostheses were analyzed by supercritical fluid chromatography (SFC) and high temperature gas chromatography (GC) coupled with direct deposition FT-IR detection. The chromatographic resolution and deposition quality were found to be unsatisfactory for SFC/FT-IR; however, high temperature GC/FT-IR produced excellent results. The chromatograms and spectra obtained allowed for the identification of poly-dimethyl silicones and mono-, di-, and tri-diphenylsubstituted poly-dimethyl silicones. An automated method of baseline correction was developed that allowed functional group chromatograms due to molecules containing Si-phenyl bonds to be constructed without significant interference from Si-methyl bonds despite the fact that the Si-C stretching mode of Si-phenyl bands overlapped significantly with the strong bands due to Si-CH3 groups.

Characterization of silicones by direct-deposition GC/FT-IR

Coupling thin layer chromatography (TLC) with diffuse reflectance infrared spectrometry facilitates the analysis of coal extracts. Like coal itself, the extracts are composed of a complex mixture of many different components. After the easy, inexpensive TLC separation of the extracts into broad classes, the components are transferred simultaneously to a series of cups from which their diffuse reflectance spectra may be measured. The cups are packed with a chalcogenide matrix, which is transparent through much of the mid infrared. Because chromatographic resolution is preserved in the transfer, infrared spectra of all the separated component classes may be obtained. Studying various extracts of three different coals allows for investigation of the molecular differences between them thus providing valuable information concerning the structure of coal.

Thin Layer Chromatography/Diffuse Reflectance Fourier Transform Infrared Spectrometry Of Coal Extracts

I was delighted and truly honoured to receive the first Gerald S. Birth Award in Near Infrared Spectroscopy for a series of three papers on the use of rare earth standards for calibrating near infrared (NIR) spectrometers. The major contributors to these papers were Husheng Yang, a postdoctoral associate in my group who is now working at AstraZeneca, Tomas Isaksson, who was on sabbatical leave from the Agricultural University of Norway, and Richard Jackson, a former postdoc in my group who is now Manager of Applications Research at Bruker Optics, where he has worked for the past eight years. The first of these papers concerned the accurate measurement of bands in the NIR diffuse reflection spectrum of a mixture of lanthanide oxides (Er2O3, Dy2O3, Ho2O3) and talc supplied to us by Gabor Kemeny of Kemtech. This sample is similar to NIST Standard Reference Material (SRM) 1920a, but with the addition of talc to fill in some important gaps in the wavelength coverage. No NIR spectrometer has an exactly accurate wavelength/wavenumber scale. This statement is as true for FT-NIR spectrometers as grating monochromators. Even though many spectroscopists believe that, because sampling in FT-IR spectrometers is triggered by the zero-crossings of the interferogram of a helium–neon laser, the wavenumber scale should be a more accurate scale than other types of instruments; this is a myth that is taking many years to die. (The wavenumber scale of these instruments is more precise, i.e. reproducible, than other types of spectrometers, but not necessarily more accurate.) In practice, however, FT-NIR spectrometers have a major advantage in that any error in their wavenumber scale is directly proportional to the wavenumber. Errors in the frequency scale can be eliminated by simply adjusting the value of the wavenumber of the He–Ne laser that is used in the calculation of the spectrum. To determine the wavenumber error of each instrument used in this roundrobin study, it was first necessary to find suitable lines in the spectrum of water vapour in order to calibrate the wavenumber scale of each instrument. Out of 3768 lines reported to be in the first overtone of the H–O–H stretching made of water vapour, only two (at 7306.7518 cm and 7294.1229 cm) fulfilled the criterion that they were separated by at least 1 cm from neighbouring lines having no more than 5% of their intensity. In practice, therefore, these are the only lines in the NIR spectrum that can be used to set the wavenumber scale of FT-NIR spectrometers. Using round robin measurements in our labs and labs at Sandia National Lab and Pike Technology, we demonstrated that it is possible to determine the wavenumbers of over 20 bands in the spectrum of this sample to an accuracy of better than 0.1 cm (or a wavelength of close to 0.01 nm). In two subsequent papers that were published in the Journal of Near Infrared Spectroscopy, we reported a careful study into the effect of resolution on the wavenumber and wavelength of these lines. We first investigated the effect of resolution on spectra measured at constant wavenumber resolution on FT-NIR spectrometers. We demonstrated that certain bands are far more susceptible to the effect of resolution than others and made recommendations as to the best bands to use for measurements made at “high” (3–10 cm) and “low” resolution (25–64 cm). The ten “best” bands for “high-resolution” spectra could be measured with a precision of ≤ 0.15 cm, and an accuracy ≤ 0.30 cm, independent of the resolution used for the measurements. For “low resolution” measurements, six bands could be measured with a precision of ≤ 0.2 cm and an accuracy of ≤ 2 cm. Spectra were calculated with 2× zero-filling and Gaussian apodisation. Wavelengths were selected using polynomial baseline correction. Only peaks that were resolved over the entire range of resolutions investigated are suitable as wavenumber standards and these bands are listed in Table 1. In the final paper of this series, the corresponding data for spectra meaThe IDRC Gerry Birth Award Lecture

Peter R. Griffiths

Papers

Advantages And Disadvantages Of A Chromatographic/FT-IR Interface Based On Mobile Phase Elimination

Characterization of silicones by direct-deposition GC/FT-IR

Thin Layer Chromatography/Diffuse Reflectance Fourier Transform Infrared Spectrometry Of Coal Extracts

The IDRC Gerry Birth Award Lecture

Standard hydrogen electrode challenge