PROTONATION OF PHOSPHINYLMETHYLPYRIDINES AND THEIR N-OXIDES IN NITROMETHANE

Article abstract of DOI:10.1007/BF00958580

The protonation of phosphinylmethylpyridines with different structures and their N-oxides differing both in the nature and the number of functional groups (pyridine nitrogen, N -> O, and P=O) was studied by potentiometric titration in nitromethane and IR spectroscopy.Regardless of the number of P=O groups, all the investigated phosphinylmethylpyridines were N bases, and their pK values changed in the range 10.4-4.7.In the case of N-oxides of phosphinylmethylpyridines, the oxygen atoms of N -> O and P=O groups participated simultaneously in protonation, and the pK values were 6.7-5.0.The structure of the protonation products is discussed.