H-transfer motions in an H-bonded (chloranilic acid)-(1,3-diazine) 1:2 molecular complex studied by 35Cl NQR and 1H NMR

Cl-35 NQR and H-1 NMR relaxation times (T-1Q, T-1H) Were measured in a hydrogen-bonded (chloranilic acid)-(1,3-diazine) 1:2 molecular complex in a temperature range of ca. 100-300 K. NQR frequencies observed were explained by the monovalent (1-) ionic structure of chloranilic acid, implying partial H-transfer to diazine molecules. This H-transfer was shown to be dynamic by observing a single T-1H minimum at ca. 120 K. Two new relaxation processes observed by NQR in high-temperature range, but undetected by NMR, were shown to be H-transfer motions between differently charged states of chloranilic acid molecules.