Origin of the Spectrum

With sets of rules providing the facts from which a full model can be constructed, the program is informed regarding the origin of the spectrum to be analyzed. A coirparison is then made between model and actual spectra. Anomalous features are thus identified. 

It should be pointed out that once the zf origin of the different bands is determined (in particular the true and false origins of the spectrum), a complete description could be given for the spin-orbit perturbations that give the lowest triplet state its radiative properties. A very extensive work was conducted by Tinti and El-Sayed (39) in which different perturbations—e.g., heating, applying a magnetic field, as well as saturation of the zf transitions with microwave radiation-were used to determine the property of the individual zf levels. The effect of these perturbations not only on the phosphorescence spectrum but also on the observed decays and polarizations has been examined. Limits on the importance of the different spin-orbit interactions are obtained. This spectroscopic work represents the type of experiments that can be done and the kind of information that can be obtained from PMDR and other methods. 

If the 0-0 band were observable in this spectrum it would be called the origin of the transition. The 4 1 band is... 

The most important feature of the Fourier analysis is the reduction of the multicoUi-nearity and ike dimension of ike original specira. However, ihe Fourier coefficients hear no. simple relationship to individual features of the spectrum so that it will not he clear what information is being used in calibration."... 

Interestingly, if the original comparison of the spectrum from the reference compound with stored m/z data for that compound reveals discrepancies, the stored reference data are updated before the computer goes on to acquire data from the unknown compound. In this mode, the computer is not used simply to acquire and manipulate data but is also used to make decisions... 

Gelbart (1974) has reviewed a number of theories of the origins of the depolarized spectrum. One of the simplest models is the isolated binary collision (IBC) model of McTague and Bimbaum (1968). All effects due to the interaction of three or more particles are ignored, and the scattering is due only to diatomic collision processes. In the case that the interacting particles A and B are atoms or highly symmetrical molecules then there are only two unique components of the pair polarizability tensor, and attention focuses on the anisotropy and the incremental mean pair polarizability... 

In similar fashion, we have plotted the spectrum of a third sample which contains 3 concentration units of Component I and none of Component 2. Of course, this spectrum also lies in the same direction from the origin as the first spectrum and at 3 times the distance. It is clear that, when we use this approach to plot the spectra of samples which contain only Component 1, each such spectrum must lie somewhere along a line extending from the origin of the data space in some unique direction that is determined by the relative absorbances of Component 1 at each of the wavelengths plotted. 

The reaction can be followed by proton magnetic resonance spectroscopy. The original absorption for the vinyl proton disappears and two new absorption peaks appear, one in the vinyl region (ca. <5 6.5, chloroform-d) and the other in the methine region of the spectrum. There are two products formed, presumably the cis- and tfraws-isomers, in the ratio of 95 5, respectively. The checkers also obtained the same yield when the reaction quantities were doubled. 

Without any restrictions we may shift the origin of the frequency scale to the centre of gravity of the spectrum ... 

Explain the origin of the lines in the spectrum of an element and correlate them with specific energy transitions (Example 1.2). 

Figure 5.40 Product-ion spectrum of the (M + H)+ ion (m/z 614) of Indinavir with the proposed origins of the ions observed. Reprinted by permission of Elsevier Science from Identification of in vitro metabolites of Indinavir by Intelligent Automated LC-MS/MS (INTAMS) utilizing triple-quadrupole tandem mass spectrometry , by Yu, X., Cui, D. and Davis, M. R., Journal of the American Society for Mass Spectrometry, Vol. 10, pp. 175-183, Copyright 1999 by the American Society for Mass Spectrometry.

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