EaStCHEM and School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh, EH9 3FJ, UK.
Nanoscale. 2019 Feb 7;11(6):2668-2678. doi: 10.1039/c8nr07088a.
Gas phase photoelectron spectroscopy (Rydberg Fingerprint Spectroscopy), TDDFT calculations and low temperature STM studies are combined to provide detailed information on the properties of the diffuse, low-lying Rydberg-like SAMO states of isolated Li@C60 endohedral fullerenes. The presence of the encapsulated Li is shown by the calculations to produce a significant distortion of the lowest-lying S- and P-SAMOs that is dependent on the position of the Li inside the fullerene cage. Under the high temperature conditions of the gas phase experiments, the Li is mobile and able to access different positions within the cage. This is accounted for in the comparison with theory that shows a very good agreement of the photoelectron angular distributions, allowing the symmetry of the observed SAMO states to be identified. When adsorbed on a metal substrate at low temperature, a strong interaction between the low-lying SAMOs and the metal substrate moves these states to energies much closer to the Fermi energy compared to the situation for empty C60 while the Li remains frozen in an off-centre position.
气相光电光谱（里德堡指纹光谱）、TDDFT 计算和低温 STM 研究相结合，为孤立的 Li@C60 笼内富勒烯中扩散的低能 Rydberg 类 SAMO 态的性质提供了详细信息。计算表明，封装的 Li 的存在导致最低 S 和 P-SAMO 发生显著变形，这取决于 Li 在富勒烯笼内的位置。在气相实验的高温条件下，Li 是可移动的，能够进入笼内的不同位置。这在与理论的比较中得到了说明，理论显示光电电子角分布非常吻合，允许确定观察到的 SAMO 态的对称性。当在低温下吸附在金属衬底上时，低能 SAMO 与金属衬底之间的强烈相互作用将这些态的能量移动到更接近费米能级的位置，与空 C60 的情况相比，而 Li 仍然冻结在偏离中心的位置。
