Spectroscopy, measuring

Frohlich, H. Using Infrared Spectroscopy Measurements to Study Intermolecular Hydrogen Bonding, /. Chem. Educ. 1993, 70, A3-A6. 

Wackerhage, H., Mneller, K., Hoffmann, U., et al., 1996. Glycolytic ATP production estimated from "" P magnetic resonance spectroscopy measurements during ischemic exercise in vivo. 4 151-155. 

Experimental methods of IR spectroscopy measurements can be divided into three main groups ... 

Information exists about the use of measuring cells made entirely of diamond or graphite with or without embedded diamond windows. Diamond cells were used, for instance, by Toth and Gilpatrick [333] in the investigation of the Nb(IV) spectrum in a LiF - BeF2 molten system at 550°C. Windowless graphite cells for the IR spectroscopy of melts were developed by Veneraky, Khlebnikov and Deshko [334]. Diamond, and in some cases windowless sapphire or graphite micro-cells, were also applied for Raman spectroscopy measurements of molten fluorides. 

The combination of photocurrent measurements with photoinduced microwave conductivity measurements yields, as we have seen [Eqs. (11), (12), and (13)], the interfacial rate constants for minority carrier reactions (kn sr) as well as the surface concentration of photoinduced minority carriers (Aps) (and a series of solid-state parameters of the electrode material). Since light intensity modulation spectroscopy measurements give information on kinetic constants of electrode processes, a combination of this technique with light intensity-modulated microwave measurements should lead to information on kinetic mechanisms, especially very fast ones, which would not be accessible with conventional electrochemical techniques owing to RC restraints. Also, more specific kinetic information may become accessible for example, a distinction between different recombination processes. Potential-modulation MC techniques may, in parallel with potential-modulation electrochemical impedance measurements, provide more detailed information relevant for the interpretation and measurement of interfacial capacitance (see later discus-... 

The calculations reveal one striking difference between Cu and Ag it is found that it requires only 4 kcal/mole for the Cu atoms to move into the plane of the surface Si atoms whereas for Ag this geometry is 53 kcal/mole higher than the ground state - even when the nearest Si atoms are allowed to move away from the noble metal atom. Thus, Cu is seen to penetrate fairly easily into the Si lattice whereas Ag stays above the surface. These theoretical findings are substantiated by thermal desorption and Auger spectroscopy measurements (48) showing that at elevated temperatures Ag desorbs into the gas phase whereas Cu remains in the solid phase. 

Circular dichroism (c.d.) spectroscopy measures the difference in absorption between left- and right-circularly polarized light by an asymmetric molecule. The spectrum results from the interaction between neighboring groups, and is thus extremely sensitive to the conformation of a molecule. Because the method may be applied to molecules in solution, it has become popular for monitoring the structure of biological molecules as a function of solvent conditions. 

Mossbauer. The Mossbauer emission spectroscopy measurements were made using the Co 7 doped catalyst as a stationary source. The moving absorber was Fe enriched K4Fe(CN) -3H20. Both the Co 7 and the absorber were obtained from New England Nuclear. The con-... 

Spectroscopy The science of analyzing the spectra of atoms and molecules. Emission spectroscopy deals with exciting atoms or molecules and measuring the wavelength of the emitted electromagnetic radiation. Absorption spectroscopy measures the wavelengths of absorbed radiation. 

Jerkiewicz G, Vatankhah G, Lessard J, Soriaga MP, Park YS. 2004. Surface-oxide growth at platinum electrodes in aqueous H2SO4 Reexamination of its mecharusm through combined cyclic-voltammetry, electrochemical quartz-crystal nanobalance, and Auger electron spectroscopy measurements. Electrochim Acta 49 1451-1459. 

One of the limitations of the portable field survey instruments in the measurement of americium is that their quantitative accuracy depends on how well the lateral and vertical distribution of americium in the soil compares with the calibration parameters used. These methods can provide a rapid assessment of americium levels on or below surfaces in a particular environment however, laboratory-based analyses of samples procured from these environmental surfaces must be performed in order to ensure accurate quantification of americium (and other radionuclides). This is due, in part, to the strong self absorption of the 59.5 keV gamma-ray by environmental media, such as soil. Consequently, the uncertainty in the depth distribution of americium and the density of the environmental media may contribute to a >30% error in the field survey measurements. Currently, refinements in calibration strategies are being developed to improve both the precision and accuracy (10%) of gamma-ray spectroscopy measurements of americium within contaminated soils (Fong and Alvarez 1997). 

Figure 7.44 shows the 2D UV chromatogram (RPLC-UV/VIS (DAD)) for a five-compound test mixture of polymer additives [662]. Any spectral data collected during hyphenated chromatography-spectroscopy measurements can be readily transformed into 2D correlation spectra. 

Zinc dialkyldithiophosphates (ZDDPs), which act as antiwear additives in lubricating oils and were postulated to exist in various molecular forms (monomer, dimer or neutral form, and basic form), were studied by multi-edge (Zn K-, P K- and S K-) XAS for structural assessment [311]. Grazing incidence absorption spectroscopy measurements have provided evidence for breakdown of the ZDDP molecule following its adsorption on to a steel substrate surface [312]. XANES and CEMS were used to study the interaction of per-fluoropolyalkyl ether (PFPAE) additives with Fe-based alloys [313],... 

Iwahashi, M. Hayashi, Y. Hachiya, N. Matsuzawa, H. Kobayashi, H., Self-association of octan-l-ol in the pure liquid state and in decane solutions as observed by viscosity, selfdiffusion, nuclear magnetic resonance and near-infrared spectroscopy measurements, J. Chem. Soc. Faraday Trans. 89, 707-712 (1993). 

Figure 10.15. X-ray photoelectron spectroscopy measurements on prereduced Pd/LaCo03 into Pd0/CoO c/La2O3 after successive exposures under reaction conditions 0.15vol.% NO, 0.5vol.% H2 and 3 vol.% 02. Photopeaks Pd 3d and N Is recorded on the calcined sample in air at 400°C (a) after reduction in H2 at 500°C (b) after exposure under reaction conditions at 25°C (c) at 200°C for 30 min (d) at 300°C for 30 min (e) at 300°C for 2h (f) at 500°C for 30min (g) and at 500°C for 2h (h) (reproduced with permission from Ref. [117]).

An extremely rare example of a six-coordinate platinum(II) complex has been prepared by the reaction of [Pt(dmpe)2]2+ with three equivalents of I2 in H20/EtOH solution which affords black crystals of [PtI(dmpe)2(K-I2)]I3 (102). X-ray crystallography reveals a neutral I2 ligand that is coordinated to the metal center through one of the iodine atoms.278 XPS (X-ray photoelectron spectroscopy) measurements are consistent with the platinum center having a +2 oxidation state. 

The structures of the new bicyclic peroxides have been established by the usual combination of physical techniques and chemical transformations. Here we highlight features of the H and 13C n.m.r. spectroscopic data that provide the best characterization of these compounds their reactions are discussed later. Information about the C-O-O-C dihedral angle in organic peroxides is potentially available from photoelectron (PE) spectroscopy. Measurements on comparatively rigid systems play an important part in establishing a soundly based experimental correlation, and the results obtained on several of these bicyclic peroxides are presented in this section also. 

Smidt CR, Gellermann W, and Zidichouski JA (2004), Non-invasive Raman spectroscopy measurement of human carotenoid status, Fed. Am. Soc. Exp. Biol. J. 18 A 480. 

In (8), the solvent-independent constants kr, kQnr, and Ax can be combined into a common dye-dependent constant C, which leads directly to (5). The radiative decay rate xr can be determined when rotational reorientation is almost completely inhibited, that is, by embedding the molecular rotor molecules in a glass-like polymer and performing time-resolved spectroscopy measurements at 77 K. In one study [33], the radiative decay rate was found to be kr = 2.78 x 108 s-1, which leads to the natural lifetime t0 = 3.6 ns. Two related studies where similar fluorophores were examined yielded values of t0 = 3.3 ns [25] and t0 = 3.6 ns [29]. It is likely that values between 3 and 4 ns for t0 are typical for molecular rotors. 

M. Bennati, A. Weber, J. Antonie, D.L. Perlstein, J. Robblee and J. Stubbe, Pulsed ELDOR spectroscopy measures the distance between the two tyrosyl radicals in the R2 subunit of the E. coli ribonucleotide reductase, J. Am. Chem. Soc., 2003, 125, 14988. 

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