Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
Phys Chem Chem Phys. 2019 Dec 7;21(45):25362-25368. doi: 10.1039/c9cp04790e. Epub 2019 Nov 8.
We investigate the photodissociation of helium-solvated cesium dimer cations using action spectroscopy and quantum chemical calculations. The spectrum of CsHe shows three distinct absorption bands into both bound and dissociative states. Upon solvation with further helium atoms, considerable shifts of the absorption bands are observed, exceeding 0.1 eV (850 cm) already for CsHe, along with significant broadening. The shifts are highly sensitive to the character of the excited state. Our calculations show that helium atoms adsorb on the ends of Cs. The shifts are particularly pronounced if the excited state orbitals extend to the area occupied by the helium atoms. In this case, Pauli repulsion leads to a deformation of the excited state orbitals, resulting in the observed blue shift of the transition. Since the position of the weakly bound helium atoms is ill defined, Pauli repulsion also explains the broadening.
我们使用作用光谱法和量子化学计算研究了氦溶剂化铯二聚阳离子的光解。CsHe 的光谱显示出三个明显的吸收带，分别进入束缚态和离解态。进一步用氦原子溶剂化后，观察到吸收带发生了相当大的位移，对于 CsHe 来说，已经超过了 0.1 eV（850 cm），同时还伴随着显著的展宽。这些位移对激发态的性质非常敏感。我们的计算表明，氦原子吸附在 Cs 的两端。如果激发态轨道延伸到氦原子占据的区域，位移就特别明显。在这种情况下，泡利排斥导致激发态轨道发生变形，从而导致观察到的跃迁蓝移。由于弱束缚的氦原子的位置不确定，泡利排斥也解释了展宽。
