A MULTINUCLEAR NMR INVESTIGATION OF SOME BENZOTRIAZOLES IN SOLUTION AND THE SOLID-STATE

Four potentially tautomeric benzotriazoles were studied in solution bo th before and following protonation, and in the solid state using H-1, C-13 and N-15 NMR measurements. Ab initio GIAO-CHF shielding calculat ions were performed to assist in H-1, C-13 and N-15 Signal assignments . At room temperature rapid prototropic exchange is observed in soluti ons of all four compounds. Protonation by trifluoroacetic acid occurs at N-3 (N-1) in all cases. In the solid samples only non-exchanging st able structures were observed on the NMR time scale. In two cases non- exchanging stable structures were observed for solutions at temperatur es below 230 K.