Ultrafast Vibrational Cooling Inside of a Molecular Container
Ultrafast Vibrational Cooling Inside of a Molecular Container
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DOI：
10.1021/acs.jpclett.9b00406
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发表时间：
2019-05-16
影响因子：
5.7
通讯作者：
Piotrowiak, Piotr
中科院分区：
文献类型：
--
作者：
Aulin, Yaroslav V.;Liu, Mengdi;Piotrowiak, Piotr
用泵浦-探测光谱研究了包裹在半导体分子容器中的甘菊环的振动冷却。在1.5 ps的激发的S-1状态，快速的内部转换通过一个圆锥形的交叉导致形成的振动热（类似于1080 K）的基态，随后的冷却，可以通过跟踪的红移的热带在基态吸收的边缘的演变进行监测。发现在主客体复合物中，甘菊环热SO态的降温速度比在普通有机溶剂中快2-4倍。如此大的加速度指向高密度的匹配振动模式和客体与主体之间的有效机械耦合。分子动力学模拟的结果完全证实了实验观察。
Vibrational cooling of azulene encapsulated in a hemicarcerand molecular container was studied by pump-probe spectroscopy. Within 1.5 ps of excitation of azulene to the S-1 state, rapid internal conversion through a conical intersection leads to the formation of a vibrationally hot (similar to 1080 K) ground state, the subsequent cooling of which can be monitored by tracking the evolution of the red-shifted hot band at the edge of the ground-state absorption. It was found that the cooling of the hot So state of azulene in the host-guest complex (hemicarceplex) is 2-4 times faster than that in common organic solvents. Such large acceleration points to a high density of matching vibrational modes and efficient mechanical coupling between the guest and the host. The experimental observations were fully corroborated by the results of molecular dynamics simulations.