Solid state ^(13)C NMR spectra of a series of naphthol-1 and naphthol-2-arylazo--deriva- tives were studied and compared with respective results in solutions.Signals of carbon nuclei of naphthalene ring were assigned....Solid state ^(13)C NMR spectra of a series of naphthol-1 and naphthol-2-arylazo--deriva- tives were studied and compared with respective results in solutions.Signals of carbon nuclei of naphthalene ring were assigned.Tautomeric forms of compounds were determined.It was shown that 4-(p-NO_2C_6H_4)-azonaphthol-1 and 1-(p-NO_2C_6H_4)-azonaphthol-2 in solid state existed ex- clusively in quinohydrazone form.The other two compounds——1-(C_6F_5)-azonaphthol-2 and 2-(p- CH_3C_6H_4)-azonaphthol-1 in solid state were not found in the form of individual tautomeric mixtures but in respective tautomeric equilibrium form.Thus,during transition from liquid to solid state, the tautomeric equilibrium was practically unchanged.In solid state it was found that rotation around aryl-N bond was hindered in the time scale of NMR spectroscopy.展开更多
基金The project was supported by the National Natural Science Foundation of China.
文摘Solid state ^(13)C NMR spectra of a series of naphthol-1 and naphthol-2-arylazo--deriva- tives were studied and compared with respective results in solutions.Signals of carbon nuclei of naphthalene ring were assigned.Tautomeric forms of compounds were determined.It was shown that 4-(p-NO_2C_6H_4)-azonaphthol-1 and 1-(p-NO_2C_6H_4)-azonaphthol-2 in solid state existed ex- clusively in quinohydrazone form.The other two compounds——1-(C_6F_5)-azonaphthol-2 and 2-(p- CH_3C_6H_4)-azonaphthol-1 in solid state were not found in the form of individual tautomeric mixtures but in respective tautomeric equilibrium form.Thus,during transition from liquid to solid state, the tautomeric equilibrium was practically unchanged.In solid state it was found that rotation around aryl-N bond was hindered in the time scale of NMR spectroscopy.
