School of Physics and Astronomy, University of Nottingham, , Nottingham NG7 2RD, UK.
Philos Trans A Math Phys Eng Sci. 2013 Aug 5;371(1998):20110627. doi: 10.1098/rsta.2011.0627. Print 2013 Sep 13.
The quantum dynamics of a hydrogen molecule encapsulated inside the cage of a C60 fullerene molecule is investigated using inelastic neutron scattering (INS). The emphasis is on the temperature dependence of the INS spectra which were recorded using time-of-flight spectrometers. The hydrogen endofullerene system is highly quantum mechanical, exhibiting both translational and rotational quantization. The profound influence of the Pauli exclusion principle is revealed through nuclear spin isomerism. INS is shown to be exceptionally able to drive transitions between ortho-hydrogen and para-hydrogen which are spin-forbidden to photon spectroscopies. Spectra in the temperature range 1.6≤T≤280 K are presented, and examples are given which demonstrate how the temperature dependence of the INS peak amplitudes can provide an effective tool for assigning the transitions. It is also shown in a preliminary investigation how the temperature dependence may conceivably be used to probe crystal field effects and inter-fullerene interactions.
使用非弹性中子散射（INS）研究了封装在 C60 富勒烯分子笼中的氢分子的量子动力学。重点是 INS 光谱的温度依赖性，这些光谱是使用飞行时间光谱仪记录的。氢内 fullerene 系统具有高度的量子力学性质，表现出平移和旋转量子化。通过核自旋异构体，揭示了泡利不相容原理的深远影响。INS 被证明非常能够驱动光子光谱学中自旋禁止的正氢和仲氢之间的跃迁。给出了在 1.6≤T≤280 K 的温度范围内的光谱，并且给出了一些示例，说明了 INS 峰幅度的温度依赖性如何可以有效地用作分配跃迁的工具。在初步研究中还表明，温度依赖性如何可能用于探测晶体场效应和内 fullerene 相互作用。
