Huang Dao-Ling, Dau Phuong Diem, Liu Hong-Tao, Wang Lai-Sheng
Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
J Chem Phys. 2014 Jun 14;140(22):224315. doi: 10.1063/1.4881421.
High-resolution photoelectron imaging and spectroscopy of cold C₆₀⁻ anions are reported using a newly built photoelectron imaging apparatus coupled with an electrospray ionization source and a temperature-controlled cryogenic ion trap. Vibrationally resolved photoelectron spectra are obtained for the detachment transition from the ground state of C₆₀⁻ to that of C60 at various detachment wavelengths from 354.84 nm to 461.35 nm. The electron affinity of C60 is accurately measured to be 2.6835 ± 0.0006 eV. Numerous unexpected vibrational excitations are observed in the photoelectron spectra due to the Jahn-Teller effect in C₆₀⁻ and Hertzberg-Teller vibronic coupling in both C₆₀⁻ and C60. Both the relative intensities of vibrational peaks and their photoelectron angular distributions provide evidence for the vibronic couplings. The observed p-wave-like behavior in the angular distribution of the 0₀⁰ transition suggests that the electron is detached from an s-type orbital.
报道了使用新构建的光电子成像装置结合电喷雾电离源和温度可控的低温离子阱，对冷C₆₀⁻阴离子进行高分辨率光电子成像和光谱研究。在从354.84纳米到461.35纳米的各种离解波长下，获得了从C₆₀⁻基态到C60基态的离解跃迁的振动分辨光电子能谱。精确测量出C60的电子亲和能为2.6835±0.0006电子伏特。由于C₆₀⁻中的 Jahn-Teller效应以及C₆₀⁻和C60中的Hertzberg-Teller电子振动耦合，在光电子能谱中观察到了许多意外的振动激发。振动峰的相对强度及其光电子角分布都为电子振动耦合提供了证据。在0₀⁰跃迁的角分布中观察到的类似p波的行为表明电子是从s型轨道离解的。
