Ultrafast carbon-carbon single-bond rotational isomerization in room-temperature solution

作者：Zheng Junrong^*; Kwak Kyungwon; Xie Jia; Fayer M D

来源：Science, 2006, 313(5795): 1951-1955.

DOI：10.1126/science.1132178

Generally, rotational isomerization about the carbon-carbon single bond in simple ethane derivatives in room-temperature solution under thermal equilibrium conditions has been too fast to measure. We achieved this goal using two-dimensional infrared vibrational echo spectroscopy to observe isomerization between the gauche and trans conformations of an ethane derivative, 1-fluoro-2-isocyanato-ethane ( 1), in a CCl4 solution at room temperature. The isomerization time constant is 43 picoseconds (ps, 10(-12) s). Based on this value and on density functional theory calculations of the barrier heights of 1, n-butane, and ethane, the time constants for n-butane and ethane internal rotation under the same conditions are similar to 40 and similar to 12 ps, respectively.

• 出版日期2006-9-29