PAN和PPN的HeI光电子能谱（PES）

给出了两个重要的大气污染化合物PAN和PPN的紫外光电子能谱（PES）。为了 指认PES谱,对两个分子实施了HF和OVGF方法的理论计算,并给出了它们各自的优 化几何构型、PES谱低电离能区的两个分离（PAN）为11.42 eV和12.07 eV;PPN为 11.08 eV和11.79 eV）被归于分子中主要体现“NO_2”基团贡献的最高占有分子轨 道（HOMO）和次最高占有分子轨道（SHOMO）电子电离作用结果。而PPN的第一电离 能11.08 eV低于PAN的11.42 eV,是由于PPN分子中增加的“CH_2”基团电子的给予 作用,这为PPN应具有较大的生物毒性提供合理的解释。

Photoelectron Spectroscopic (PE) Spectra of PAN and PPN Molecules

The photoelectron spectroscopic spectra (PES) of two important atmospheric pollutants, peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN), are reported. To assign the PES of the molecules both HF and OVGF (outer valence green function) methods have been performed. Moreover, the molecular geometries of the two compounds have been optimized. There are two separate peaks in the low energy region of PES (11.42 eV and 12.07 eV for PAN, 11.08 eV and 11.79 eV for PPN) resulted from respective ionizations of the electrons of the HOMO and the SHOMO, which have dominant contributions of the NO_2 group in the molecules. The first ionization energy (11.08 eV) of PPN is lower than that (11.42 eV) of PAN, which shows that PPN possesses more potent bioactivity than PAN, which is attributed to the electron donating action of the increasing "CH_2" group.