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

/pdf/quantum-mechanical-continuum-solvation-models-3edv963g14.pdf

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.

The fact that is is possible to acquire an interferogram in less than one second makes FT-IR spectrometry an excellent technique for studying transient species. By far the most important application of this rapid-scanning property is the on-line identification of peaks eluting from a gas chromatograph (GC/FT-IR). GC/FT-IR measurements using low resolution (20 cm-1) interferometers were described as early as 1967 [1], but only recently have GC/FT-IR measurements combining both adequate resolution (4 cm-1), low detection limits (less than 1 μg of sample injected into chromatograph), and sophisticated data handling become routine.

Chromatography and FT-IR Spectrometry

Ray-tracing analysis of a particular reflecting axicon, a right circular cone, for use as a retroreflector in active open-path Fourier- transform IR (OP/FT-IR) spectrometry, and the results of testing a 0.305-m aperture right circular cone using a commercial active OP/FT-IR spectrometer are presented. The ray-tracing model is based on the op- tical characteristics of a commercial single-telescope monostatic OP/ FT-IR spectrometer and models the off-axis behavior normally encoun- tered under practical field conditions during field use. Of practical concern are the trends for the diameter of the beam reflected from the retroreflector as a function of the path length between spectrometer and retroreflector and misalignment of the retroreflector with respect to the transmitted beam. Construction and the results of field-testing two smaller epoxy-composite axicons replicated from the 0.305-m master are presented. © 2003 Society of Photo-Optical Instrumentation Engineers.

Axicon as a retroreflector in open-path Fourier transform infrared spectrometry

Although the use of transform techniques in analytical chemistry and applied spectroscopy has only become widespread in the past five years, the history of this subject can be traced back to the middle of the nineteenth century when the effect of the interference of light was first used to derive spectroscopic information In 1862, Fizeau(1) used Newton’s rings to show that the yellow sodium radiation was a doublet whose separation was 1/980 of their average wavelength At the end of the century Michelson designed the interferometer, which now bears his name(2,3) The initial uses of this instrument for spectroscopic purposes concerned the determination of spectral profiles through the use of the visibility technique,(4) which is essentially a study of the envelope of what we now call the interferogram Rayleigh(5) pointed out that a unique spectral distribution cannot be found from the visibility curve itself, and the Fourier transform of the interferogram is needed to calculate the spectrum unequivocally

Transform Techniques in Chemistry: Past, Present, and Future

Sampling the Interferogram

Three ways in which on-line infrared (IR) spectra of species eluting from a gas chromatograph (GC) are described in this chapter. The first, and most simple, involves passing the effluent from the GC through a long, narrow gas cell, or light-pipe. Since vapor-phase spectra are measured using this technique, identification requires a library of vapor-phase reference spectra. The second technique, which is at least an order of magnitude more sensitive, involves adding a small amount of argon to the helium carrier and condensing the argon along with each chromatographically separated component on a moving gold-coated substrate and measuring the transflection spectrum. Bands in the matrix-isolated spectra of each component are very narrow but require a special library to allow spectral searching. The third, and most sensitive, technique involves condensing each component as a very small spot on a moving ZnSe window and measuring the transmission spectrum shortly after deposition. Spectra measured in this way are very similar to KBr disk reference spectra, for which extensive libraries are available. The detection limits may be reduced by at least an order of magnitude by vapor-depositing a thin layer of silver on the ZnSe plate.

Peter R. Griffiths

Papers

Chromatography and FT-IR Spectrometry

Axicon as a retroreflector in open-path Fourier transform infrared spectrometry

Transform Techniques in Chemistry: Past, Present, and Future

Sampling the Interferogram

GAS CHROMATOGRAPHY | Infrared Spectroscopy