Plotting ID Spectra

Plotting NMR spectra is never a job of secondary importance. To obtain the best results a few rules should be followed when preparing the page layout. Besides the spectrum itself, the layout should contain all relevant information, including the acquisition and processing parameters and a spectrum title. The acquisition and processing parameters are necessary to interpret and understand the spectrum and to allow the experiment to be repeated under the same conditions to reproduce and confirm the results. These parameters are also needed when preparing the experimental part of your thesis or a publication. The spectrum title should immediately identify the sample that has been measured and the experiment that has been performed. 

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Stacked plot The 2D NMR spectrum is presented as a series of ID spectra parallel to the F axis stacked together at a number of values (or vice versa), one below the other. 

FIGURE 18. Selected portion of a HETCOR plot of 73a (13 mgml 1 CDCI3). Projections along the axes are ID spectra obtained at 360 MHz for 1II and 90 MHz for 13C. The spectra contain additional olefinic signals at 141.76(C(8 )), 110.81(C(7 )) and 7.18 (d, H—C(8 )) ppm. Reproduced by permission of Neue Schweizerische Chemische Gesellschaft from Reference 43... 

Last but not least the familiarity with displaying and plotting ID- and 2D NMR spectra is a prerequisite to inspect, understand and evaluate the results obtained with the many processing options discussed in chapter 5. 

In addition to the display functions offered in the buttons panel, the Display pulldown menu (Fig. 4.22) contains additional options for controlling the display of the 2D matrix and its related spectral elements. It is possible to display standard ID spectra, projections or slices on the Fl or F2 axis of a 2D plot together with the 2D spectrum. It is also possible to create additional expansion windows which can be moved, resized and deleted. 

As already outlined for ID spectra, plotting of NMR data is by no means a task of secondary importance. The choice of suitable expansions, the completeness of additional data, including the relevant acquisition, processing and plot parameters, an appropriate title and a structural formula if available facilitate the subsequent spectral analysis. 

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