H-1 AND C-13 NMR AND FT-IR STUDIES OF THE INTERACTION BETWEEN 1,8-BIS(DIMETHYLAMINO)NAPHTHALENE AND 3,5-DICHLOROPHENOL

The H-1 and C-13 NMR spectra of the complex between 1,8-bis(dimethylam ino)naphthalene and 3,5-dichlorophenol have been studied at temperatur es between 30 degrees C and -70 degrees C in CD2Cl2 and at different a cid to base concentration ratios. At a temperature of -60 degrees C a splitting of the H-1 and C-13 signals of DMAN and DMANH(+) is observed . The protonation degree deduced from the NMR data and the intensity o f the Bohlmann bands are in very good agreement. At a temperature belo w 8 degrees C, a splitting (2.6 Hz) of the methyl protons caused by sp in-spin coupling with the (NHN)(+) bridge protons is observed. Compari son with literature data and with the coupling constant determined in this work for protonated N,N-dimethylaniline suggest that the potentia l surface of the NHN+ cation includes two symmetrically situated wells between which fast proton migration takes place.