A protonic motion in the 1-D hydrogen-bonded zigzag chain in 4,6-dimethylpyrimidinium hydrogen chloranilate,[4,6-dmpH][Hca], was studied from the measurements of Cl-35 nuclear quadrupole resonance (NQR) spin-lattice relaxation time (T-1). The four NQR frequencies were observed at 36.846, 36.767, 35.945, and 35.905 MHz at 77 K. The temperature dependences of these frequencies were smooth and continuous in 77-360K. The absence of solid-solid phase transition and the metastable phase was confirmed by heat capacity measurements. Temperature dependence of the NQR T-1 suggests an excitation of a motion above ca. 200K with the activation energy of 11.5 kJ mol(-1). In the stable phase too, the excitation of proton transfer is expected to occur as suggested for the metastable phase of as-grown crystals. Such transfer motion may be possible at the kink structure of the 1-D ferroelectric zigzag chain, and the kink can migrate in the chain accordingly. (C) 2011 Elsevier B.V. All rights reserved.