Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
J Phys Chem A. 2009 Dec 31;113(52):14559-64. doi: 10.1021/jp9040524.
Outer valence ionic states of Cr(CO)(6) and (eta(5)-C(5)H(5))Co(CO)(2) were investigated by means of Penning ionization electron spectroscopy (PIES) upon collision with metastable He*(2(3)S) excited atoms as well as high-level ab initio molecular orbital calculations taking electron correlation effects into consideration. By the 2D measurement combining the collision-energy-resolved technique of the metastable atomic beam and electron spectroscopy, ionic-state-resolved measurement of collision energy dependence of partial ionization cross sections (CEDPICS) was carried out. Because partial Penning ionization cross sections can be connected to the spatial extent of corresponding molecular orbitals (MOs) outside the boundary surface of colliding He* atoms, different slopes of CEDPICS were related to anisotropic interaction around the MO region. The observed CEDPICS and PIES band intensity were consistent with the order of calculated ionic states.
采用 Penning 电离电子能谱（PIES）方法，通过与 He*（2(3)S）亚稳态原子碰撞，研究了 Cr(CO)(6)和（η(5)-C(5)H(5)）Co(CO)(2)的外层价离子态，同时还进行了考虑电子相关效应的高精度从头算分子轨道计算。通过结合亚稳态原子束的碰撞能分辨技术和电子能谱的二维测量，实现了对部分离化截面（CEDPICS）随碰撞能变化的离子态分辨测量。由于部分 Penning 离化截面可以与碰撞 He*原子边界以外的相应分子轨道（MO）的空间延伸相关联，因此 CEDPICS 的不同斜率与 MO 区域周围的各向异性相互作用有关。观察到的 CEDPICS 和 PIES 带强度与计算出的离子态顺序一致。
