H-Transfer Motions in an H-Bonded (Chloranilic Acid)-(1,3-Diazine) 1:2 Molecular Complex Studied by 35Cl NQR and 1H NMR

Abstract 35Cl NQR and 1H NMR relaxation times (T1Q, T1H) 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 T1H 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.