The donor numbers (DN) of a series of 20 phosphoramides with general structure (R2N)(X2N)(Y2N)P=O (with R,X and Y alkyl radicals,
nitrogen-heterocycles or hydrogen atoms) were revised on the basis of a series of rather simple considerations. It is shown that all the
phosphoramides considered even after the revision are characterized by high DN. In a scale of 163 different type of solvent molecules, the
phosphoramides are all collocated with their DN above 35 kcal mol-1
till 50 kcal mol-1
. The extremely high DN value reported previously
for (tris(1-aziridinyl)phosphine oxide (TEPA), is now revised to 50 kcal mol-1
. The highest DN values in the phosphoramides considered in
this investigation were those of TEPA, (NHEt)3P=O and (pyrrolidino)3P=O.
Key words: Gutmann donicity, solvent donor numbers, phosphoramides, (tris(1-aziridinyl)phosphine oxide, electron pair donors
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