Spectroscopy, infrared visible

Callegari A, Rebstein J, Muenter J S, Jost R and Rizzo T R 1999 The spectroscopy and intramolecular vibrational energy redistribution dynamics of HOCI in the u(OH) = 6 region, probed by infrared-visible double resonance overtone excitation J. Chem. Phys. 111 123-33... 

Zhu X D, Suhr H and Shen Y R 1987 Surface vibrational spectroscopy by infrared-visible sum frequency generation Phys. Rev. B 35 3047-59... 

Microscopy (qv) plays a key role in examining trace evidence owing to the small size of the evidence and a desire to use nondestmctive testing (qv) techniques whenever possible. Polarizing light microscopy (43,44) is a method of choice for crystalline materials. Microscopy and microchemical analysis techniques (45,46) work well on small samples, are relatively nondestmctive, and are fast. Evidence such as sod, minerals, synthetic fibers, explosive debris, foodstuff, cosmetics (qv), and the like, lend themselves to this technique as do comparison microscopy, refractive index, and density comparisons with known specimens. Other microscopic procedures involving infrared, visible, and ultraviolet spectroscopy (qv) also are used to examine many types of trace evidence. 

In order to get the pore system of zeolites available for adsorption and catalysis the template molecules have to be removed. This is generally done by calcination in air at temperatures up to 500 °C. A careful study (ref. 12) of the calcination of as-synthesized TPA-containing MFI-type single crystals by infrared spectroscopy and visible light microscopy showed that quat decomposition sets in around 350 °C. Sometimes special techniques are required, e.g. heating in an ammonia atmosphere (ref. 13) in the case of B-MFI (boron instead of aluminum present) to prevent loss of crystallinity of the zeolite during template quat removal. 

Buck, M. and Himmelhaus, M. (2001) Vibrational spectroscopy of interfaces by infrared-visible sum frequency generation. J. Vac. Sci. Technol. A, 19, 2717-2736. 

J. Phys. Chem. B, 106, 5143-5154. Somorjai, G. A. and Rupprechter, G. (1999) Molecular studies of catalytic reactions on crystal surfaces at high pressures and high temperatures by infrared-visible sum frequency generation (SFG) surface vibrational spectroscopy. J. Phys. Chem., 103, 1623-1638. 

Bonn M, Hess C, Miners JH, Heinz TP, Bakker HJ, Cho M. 2001. Novel surface vibrational spectroscopy Infrared-infrared-visible sum-frequency generation. Phys Rev Lett 86 1566-1569. 

Fourier transform infrared (FTIR) spectroscopy, 13C nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-VIS) and fluorescence spectroscopy can be integrated with chromatographic techniques especially in the study of ageing and degradation of terpenic materials. They can be used to study the transformation, depletion or formation of specific functional groups in the course of ageing. 

An electric dipole operator, of importance in electronic (visible and uv) and in vibrational spectroscopy (infrared) has the same symmetry properties as Ta. Magnetic dipoles, of importance in rotational (microwave), nmr (radio frequency) and epr (microwave) spectroscopies, have an operator with symmetry properties of Ra. Raman (visible) spectra relate to polarizability and the operator has the same symmetry properties as terms such as x2, xy, etc. In the study of optically active species, that cause helical movement of charge density, the important symmetry property of a helix to note, is that it corresponds to simultaneous translation and rotation. Optically active molecules must therefore have a symmetry such that Ta and Ra (a = x, y, z) transform as the same i.r. It only occurs for molecules with an alternating or improper rotation axis, Sn. 

Yasenkov, S. and Frei, H. (1998). Time-resolved FT-infrared spectroscopy of visible light-induced alkene oxidation by 02 in a zeolite. J. Phys. Chem. B 102, 8177-8182... 

Fergusson et al. were the first to report the existence of binary compounds with a general formula Se Sg in these melts. They carried out an extensive investigation by X-ray powder diffraction and by absorption spectroscopy in the infrared, visible, and ultraviolet regions over the whole composition range of molten mixtures of sulfur and selenium cooled down to 20 °C. They also examined phases obtained by recrystallization of the cooled melts from carbon disulfide. All phases were isomorphic with one of the allotropes of Sg and SCg indicating that the structures also consist of cyclic eight-membered molecules ... 

Another relatively new technique is the infrared visible sum frequency generation (SFG) spectroscopy and the difference frequency generation (DFG) spectroscopy [13], both of which represent vibrational spectroscopic techniques sensitive only to the material located at interfaces. 

Such a development would be impossible without the generation of new experimental techniques extending the possibilities of studies of supramolecular systems. One such new technique is the vibrational (or infrared-visible) spectroscopy sum frequency generation [8] enabling one to lookatjustthe outer monolayer, thus providing more information than more standard methods like contact angle and surface tension measurements [9]. 

E.S.Stern, "An Introduction to Electronic Spectroscopy in Organic Chemistry", St Martins,London(1958)(See also Infrared Spectroscopy, Ultraviolet Spectroscopy and Visible Spectroscopy)... 

Information about the structure of gas molecules haB been obtained by several methods. Spectroscopic studies in the infrared, visible, and ultraviolet regions have provided much information about the simplest molecules, especially diatomic molecules, and a few polyatomic molecules. Microwave spectroscopy and molecular-beam studies have yielded very accurate interatomic distances and other structural information about many molecules, including some of moderate complexity. Molecular properties determined by spectroscopic methods are given in the two books by G. Herzberg, Spectra of Diatomic Molecules, 1950. and Infrared and Raman Spectra, 1945, Van Nostrand Co., New York. The information obtained about molecules by microwave spectroscopy is summarised by C. H. Townes and A. L. Schawlow in their book Microwave Spectroscopy of Gases, McGraw-Hill Book Co., New York, 1955. 

Before the laser, the light sources used in infrared, visible, and ultraviolet spectroscopy were heated solids or gas discharge tubes. These sources are based on spontaneous emission. Such light is emitted in random directions with random phases. Even lines of gas discharge tubes lack true monochromaticity due to pressure-, Doppler-, and naturalbroadening. Thus light from these traditional sources does not possess the above-mentioned four qualities of laser light, which is based on stimulated emission. 

Microwave spectroscopy covers the frequency range from about 3 GHz to 300 GHz. The techniques used in the infrared, visible, and ultraviolet regions resemble one another closely, but the techniques of microwave spectroscopy differ considerably from those of optical spectroscopy. The source in microwave work is usually a klystron, which is an electronic tube... 

Infrared, visible and near ultraviolet spectroscopy are particularly important when used in conjunction with polarising devices in determining the mean orientation of molecules or particular parts of molecules. 

CA 49,739l(1955)(Explosive combustion of hydrocarbons — comparative investigation and study of continuous spectra) ll)H.M.Hershen-son, "Ultraviolet and Visible Absorption Spectra , Index for 25 years - 1930 to 1954, Academic Press, NY(1956) 12)A.Gillam E.S.Stern, "An Introduction to Electronic Spectroscopy in Organic Chemistry , St Martins,London(1958)(See also Infrared Spectroscopy, Ultraviolet Spectroscopy and Visible Spectroscopy)... 

The techniques considered in this chapter are infrared spectroscopy (or vibrational spectroscopy), nuclear magnetic resonance spectroscopy, ultraviolet-visible spectroscopy (or electronic spectroscopy) and mass spectrometry. Absorption of infrared radiation is associated with the energy differences between vibrational states of molecules nuclear magnetic resonance absorption is associated with changes in the orientation of atomic nuclei in an applied magnetic field absorption of ultraviolet and visible radiation is associated with changes in the energy states of the valence electrons of molecules and mass spectrometry is concerned... 

Unlike NMR spectroscopy and vibrational spectroscopy, electronic spectroscopy involves interactions with electromagnetic waves in the near-infrared, visible, and ultraviolet (UV) spectral regions. While electronic spectroscopy... 

Grum, F. in Spectroscopy and Spectrometry in the Infrared, Visible and Ultraviolet Optical, Spectroscopic and Radioactivity Methods, Part mB of Physical Methods of Chemistry, which is Vol. I of Techniques of Chemistry Weissberger, H. Rossiter, B. W. Gen. Eds Wiley-Interscience New York, 1972 715 pp. Chapter III. 

Spectroscopic properties. The techniques of optical spectroscopy (ultraviolet, visible, and infrared spectrophotometry) are often used to examine the reactants or products of an electrode reaction. Obviously the solvent (and supporting electrolyte) must be transparent at the wavelength region of interest all of the commonly used dipolar aprotic solvents are transparent in the visible region. However, those solvents that contain aromatic or conjugated unsatu-... 

Precision measurement of energy intervals in hydrogen and helium has been fundamental to the development of atomic theory. Relativistic and quantum-electrodynamic contributions scale with various powers of Z. Hence more information is gained by extending precise measurements to one- and two-electron ions. Laser spectroscopy is restricted to certain special transitions which fall in the infrared, visible or near-ultraviolet, and from which a useful signal can be obtained. However, where applicable, it provides precision tests of theory. The focus of this review is laser spectroscopy of the n = 2 levels of moderate-Z helium-like and hydrogen-like ions. Previous reviews may be found in [1,2,3],... 

Volumes 50 and 51 of the Advances, published in 2006 and 2007, respectively, were the first of a set of three focused on the physical characterization of solid catalysts in the functioning state. This volume completes the set. The six chapters presented here are largely focused on the determination of structures and electronic properties of components and surfaces of solid catalysts. The first chapter is devoted to photoluminescense spectroscopy it is followed by chapters on Raman spectroscopy ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy X-ray photoelectron spectroscopy X-ray diffraction and X-ray absorption spectroscopy. 

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