H-1 AND C-13 NMR-STUDIES OF 1,8-BIS(DIMETHYLAMINO)NAPHTHALENE SALTS IN ACETONITRILE-D3

H-1 and C-13 NMR spectra were studied for a number of 1,8-bis(dimethylamino)naphthalene (DMAN) salts in acetonitrile-d3. In the case of strong acids no counter anion effect was observed on the protonated DMAN molecules. A splitting of the H-1 signal of the CH3 groups was found which was caused by coupling with the bridge NHN+ proton. It was confirmed that the salt with pentachlorophenol (PCP) undergoes a transformation to a nearly equimolar solution of free DMAN, protonated DMAN and the homoconjugated anion of PCP. The formation of the NHN+ bridge with an equally shared proton between the two nitrogen atoms leads to a change in the charge distribution in the napthalene ring which is analogous to, but much weaker than, that found on protonation of aniline.