Czekner Joseph, Cheung Ling Fung, Kocheril G Stephen, Wang Lai-Sheng
Brown University , Department of Chemistry , 324 Brook Street , Providence , RI 02912 , USA . Email:
Chem Sci. 2018 Nov 15;10(5):1386-1391. doi: 10.1039/c8sc04771e. eCollection 2019 Feb 7.
A dipolar molecule can weakly bind an electron in a diffuse orbital. However, the spin-orbit coupling between this weakly bound electron and the electrons in the molecular core is not known. Here we probe this coupling using the linear CP anion with the Σ ground state, which possesses dipole-bound excited states because neutral CP (Π) has a sufficiently large dipole moment. Photodetachment spectroscopy and resonant photoelectron spectroscopy are used to probe the nature of the dipole-bound states. Two dipole-bound excited states are observed with a binding energy of 37 cm, corresponding to the two spin-orbit states of neutral CP (Π and Π). The current study demonstrates that the weakly bound electron in the dipole-bound excited states of CP is not spin-coupled to the electrons in the CP core and can be considered as a quasi-free electron.
偶极分子可以在弥散轨道中弱束缚一个电子。然而，这个弱束缚电子与分子核心中的电子之间的自旋 - 轨道耦合尚不清楚。在这里，我们使用具有Σ基态的线性CP阴离子来探测这种耦合，由于中性CP（Π）具有足够大的偶极矩，该阴离子具有偶极束缚激发态。光剥离光谱和共振光电子能谱被用于探测偶极束缚态的性质。观察到两个偶极束缚激发态，其束缚能为37厘米，对应于中性CP的两个自旋 - 轨道态（Π和Π）。当前的研究表明，CP偶极束缚激发态中的弱束缚电子与CP核心中的电子没有自旋耦合，可以被视为一个准自由电子。
