Spectral Presentation

A few important features related to spectral presentation are enumerated below  

From Eq. (e), one may observe that the resulting curve is independent of both cell-length and sample concentration, 

Water-common solvent for a number of inorganic substances, 

Ethanol (96% w/v)-good choice as fairly polar solvent, 

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Use standardized plotting of spectral presentations, comparable to 0-10 ppm used for proton spectra The range from -1-50 to -250 ppm covers most organofluonne signals but is too wide to show finer splitting and would require individual signals to be expanded. 

CHART AND SPECTRAL PRESENTATIONS OF ORGANIC SOLVENTS, MULLING OILS, AND OTHER COMMON LABORATORY SUBSTANCES... 

In FTIR spectroscopy, an interference wave interacts with the sample in contrast to a dispersive instrument where the interacting energy assumes a well-defined wavelength range. The interference wave is produced in an interferometer (Fig. 4.1.1), the most common of which is the Michelson interferometer. A computer is used to control the interferometer, to collect and store data, and to perform the Fourier transformation. In addition, the computer performs post-spectroscopic operations such as spectral presentation, resolution enhancement, calibration, and calculation of correlation equations. 

Nomenclature and Spectral Presentation in Electron Spectroscopy Resulting from Excitation by Photons, Pure Appl. Chem. 45 (1976) 221-224. 

As we see in Section 10.3, 2D NMR lines, including those in COSY, have a complex shape. A number of variants of COSY have been developed to improve the spectral presentation and to avoid unwanted signals. We shall return to COSY in Chapter 12. 

Now that the principles of NMR spectroscopy have been introduced, we will see how NMR spectra of the two most common nuclei—hydrogen and carbon-13—are obtained. The principles described for carbon-13 are applicable to many other spin- /2 nuclei, such as nitrogen-15, fluorine-19, silicon-29, and phosphorus-31. Topics to be discussed include the components of a typical NMR spectrometer, preparation of a sample, signal optimization techniques, spectral acquisition, selection of processing parameters, spectral presentation, and calibration of the spectrometer. 

Chart and Spectral Presentations of Organic Solvents, Mulling Oils, and Other Common Laboratory Substances... 

A brief inspection of the bar-graph spectral presentation can tell the experienced interpreter a substantial amount about the unknown molecule. You have already seen how the mass and relative abundance of the molecular ion indicate the size and general stability of the molecule (Section 3.6). In addition, the number of abundant ions in the spectrum and their distribution in the mass scale are indicative of the type of molecule and the functional groups present. For example, a glance at the spectrum of Unknown 5.1 should tell you that this is a highly stable molecule. Deduce its elemental composition this should correspond to a value for rings plus double bonds which is consistent with this stability. Not only are there no weak bonds in the molecule, but apparently the main fragmentation pathways are of approximately the same low probability. What is a possible structure ... 

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