Prediction of Donor-Acceptor Interactions

The approximately linear relationship between the donor number and the —ZIHa d values for the interactions between an acceptor A and the donor solvent D allows immediately an empirical approach to predict —zIHa d values. Calorimetric data must be available for the interactions of the given acceptor A with at least two different donors the donor numbers of which must be known. These values may be plotted against the donor numbers of the donors. From this plot —JHa.D for any D with given DNsbCU can be readily derived. [Pg.20]

Drago and Wayland have suggested a different approach to predict —zIHa D values according to [Pg.20]

When Ca, Ea and the —zJHa d values for two donors are known, calculations of —zlHa.D values for other donors can be carried out. Very good agreement between observed and calculated figures is found for A = iodine or phenol , but agreement is poor for A = trimethylboron (Table 5) and D = trimethylamine. [Pg.20]

The discrepancies are appreciable when SbCls is used as an acceptor. The parameters CsbCk and Esbcu are different for different reference bases. When methylacetate and dimethylformamide are used as reference donors Csbci5 = 5.17 and Esbci5 = 2.9, while with acetone and dimethylsulphoxide as reference donors Csbcu = 2.56 and Esbcu = 21.70. [Pg.20]

Thus the graphical approach suggested by Gutmann appears to be more convenient and more reliable than the calculation procedure. Both approaches require the same amount of experimental information, namely two —zJHa-d values representing the interactions of the acceptor towards two different donor molecules. [Pg.20]

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