Correlations Involving N-15 NMR Shifts

TABLE 6.4. Net Charges (me) and NMR Shifts of Carhonyl Carhon Atoms 

This section considers aUcylamines, nitroalkanes, isonitriles, pyridines, and diazines and offers comparisons between NMR shifts and calculated atomic charges. Most of 

Here we are concerned mainly with alkylamines. Detailed SCF charge analyses [43] indicate that any gain in total charge translates into a downfield shift, which is the trend exhibited by alkylamines, but also by nitroalkanes and isonitriles. Examples are offered in Table 6.5 (see also Fig. 6.6), along with pertinent ionization potentials, indicated in kcal/mol  

The comparison with adiabatic ionization potentials [147] indicates that the latter decrease as electronic charge builds up on nitrogen, as one would normally expect, thus suggesting that the charges calculated here are in the right order. (These ionization potentials correspond to the suppression of an electron of the lone pair on 

The charges reported in Table 6.5 are STO-3G results. They require a rescaling that described by (35.1/69.4)A ° reasonable approximation 

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