THE DYNAMICS OF HYDROGENS IN DOUBLE WELL POTENTIALS - THE TRANSITION OF THE JUMP RATE FROM THE LOW-TEMPERATURE QUANTUM-MECHANICAL TO THE HIGH-TEMPERATURE ACTIVATED REGIME
THE DYNAMICS OF HYDROGENS IN DOUBLE WELL POTENTIALS - THE TRANSITION OF THE JUMP RATE FROM THE LOW-TEMPERATURE QUANTUM-MECHANICAL TO THE HIGH-TEMPERATURE ACTIVATED REGIME
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DOI：
10.1063/1.461795
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发表时间：
1991-09-15
影响因子：
4.4
通讯作者：
HAEBERLEN, U
中科院分区：
文献类型：
--
作者：
HEUER, A;HAEBERLEN, U
给出了四种羧基被氘化的羧酸的自旋晶格弛豫时间T1随温度的变化关系。这些数据允许确定氢在双阱势的两个最小值之间的氢转移速率，其中氢沿着氢键移动。的温度依赖性的伽马有明显不同的低温量子力学和高温热激活制度。有证据表明，转移的氢在二聚体的羧酸是强烈的影响，由一个高频模式，这是强烈耦合到氢。这支持了ETH小组最近提出的结论[J.Chem.Phys.93，1502（1990）]。一个模型的基础上的自旋玻色子的哈密顿与浴声学声子加上一个独特的高频模式，充分解释了跳跃率在量子力学制度的所有四个化合物的研究。澄清了独特的浴槽模式影响氢转移的方式。
The temperature dependence of the deuteron spin lattice relaxation time T1 in four carboxylic acids, which were deuterated in the carboxyl groups, is presented. These data allow determination of the rate GAMMA of the hydrogen transfer between the two minima of the double well potential in which the hydrogens move along the hydrogen bonds. The temperature dependence of GAMMA has clearly distinct low temperature quantum-mechanical and high temperature thermally activated regimes. Evidence is presented that the transfer of hydrogens in dimers of carboxylic acids is strongly influenced by a high-frequency mode which is strongly coupled to the hydrogens. This supports the conclusions recently put forward by the ETH group [J. Chem. Phys. 93, 1502 (1990)]. A model based on the spin-boson-Hamiltonian with a bath consisting of acoustic phonons plus a unique high frequency mode explains fully the jump rate in the quantum mechanical regime of all four compounds studied. The way in which the unique bath mode influences the hydrogen transfer is clarified.