Yuan Dao-Fu, Liu Yuan, Qian Chen-Hui, Zhang Yue-Rou, Rubenstein Brenda M, Wang Lai-Sheng
Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
Phys Rev Lett. 2020 Aug 14;125(7):073003. doi: 10.1103/PhysRevLett.125.073003.
We report the observation of a π-type dipole-bound state (π-DBS) in cryogenically cooled deprotonated 9-anthrol molecular anions (9AT^{-}) by resonant two-photon photoelectron imaging. A DBS is observed 191 cm^{-1} (0.0237 eV) below the detachment threshold, and the existence of the π-DBS is revealed by a distinct (s+d)-wave photoelectron angular distribution. The π-DBS is stabilized by the large anisotropic in-plane polarizability of 9AT. The population of the dipole-forbidden π-DBS is proposed to be via a nonadiabatic coupling with the dipole-allowed σ-type DBS mediated by molecular rotations.
我们通过共振双光子光电子成像报告了在低温冷却的去质子化9-蒽醇分子阴离子（9AT⁻）中观察到π型偶极束缚态（π-DBS）。在离解阈值以下191 cm⁻¹（0.0237 eV）处观察到一个偶极束缚态，并且通过独特的（s + d）波光电子角分布揭示了π-DBS的存在。π-DBS由9AT的大的面内各向异性极化率稳定。偶极禁戒的π-DBS的布居被认为是通过与由分子旋转介导的偶极允许的σ型偶极束缚态的非绝热耦合实现的。
