| Abstract: | The temperature dependences of 1H NMR as well as 35Cl NQR spin-lattice relaxation times T 1 were investigated in order to study the hydrogen transfer dynamics in carboxylic acid dimers in 3,5-dichloro- and 2,6-dichlorobenzoic acids. The asymmetry energy A/ k B and the activation energy V/ k B for the hydrogen transfer were estimated to be 240 K and 900 K, and 840 K and 2500 K, respectively, for these compounds. In spite of a large asymmetric potential the quantum nature of hydrogen transfer is recognized in the slope of the temperature dependence of T 1 on the low-temperature side of the T 1 minimum. The NQR T 1 measurements was revealed to be a good probe for the hydrogen transfer dynamics. |
