Limão-Vieira P, Ferreira da Silva F, Almeida D, Hoshino M, Tanaka H, Mogi D, Tanioka T, Mason N J, Hoffmann S V, Hubin-Franskin M-J, Delwiche J
Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Department of Physics, Sophia University, Tokyo 102-8554, Japan.
J Chem Phys. 2015 Feb 14;142(6):064303. doi: 10.1063/1.4907200.
The electronic state spectroscopy of carbonyl sulphide, COS, has been investigated using high resolution vacuum ultraviolet photoabsorption spectroscopy and electron energy loss spectroscopy in the energy range of 4.0-10.8 eV. The spectrum reveals several new features not previously reported in the literature. Vibronic structure has been observed, notably in the low energy absorption dipole forbidden band assigned to the (4π←3π) ((1)Δ←(1)Σ(+)) transition, with a new weak transition assigned to ((1)Σ(-)←(1)Σ(+)) reported here for the first time. The absolute optical oscillator strengths are determined for ground state to (1)Σ(+) and (1)Π transitions. Based on our recent measurements of differential cross sections for the optically allowed ((1)Σ(+) and (1)Π) transitions of COS by electron impact, the optical oscillator strength f0 value and integral cross sections (ICSs) are derived by applying a generalized oscillator strength analysis. Subsequently, ICSs predicted by the scaling are confirmed down to 60 eV in the intermediate energy region. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of carbonyl sulphide in the upper stratosphere (20-50 km).
利用高分辨率真空紫外光吸收光谱和电子能量损失光谱，在4.0 - 10.8电子伏特的能量范围内对羰基硫（COS）的电子态光谱进行了研究。该光谱揭示了一些文献中此前未报道的新特征。观察到了振动电子结构，特别是在分配给(4π←3π) ((1)Δ←(1)Σ(+))跃迁的低能量吸收偶极禁戒带中，本文首次报道了一个分配给((1)Σ(-)←(1)Σ(+))的新的弱跃迁。确定了基态到(1)Σ(+)和(1)Π跃迁的绝对光学振子强度。基于我们最近通过电子碰撞对COS的光学允许((1)Σ(+)和(1)Π)跃迁的微分截面测量，通过应用广义振子强度分析得出光学振子强度f0值和积分截面（ICSs）。随后，在中间能量区域，通过标度预测的ICSs在低至60电子伏特时得到了证实。所测量的绝对光吸收截面已被用于计算平流层上部（20 - 50千米）羰基硫的光解寿命。
