Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná, Brazil.
J Chem Phys. 2013 Dec 7;139(21):214301. doi: 10.1063/1.4834776.
We report calculated cross sections for elastic collisions of low-energy electrons with halopyrimidines, namely, 2-chloro, 2-bromo, and 5-bromopyrimidine. We employed the Schwinger multichannel method with pseudopotentials to compute the cross sections in the static-exchange and static-exchange plus polarization levels of approximation for energies up to 10 eV. We found four shape resonances for each molecule: three of π* nature localized on the ring and one of σ* nature localized along the carbon-halogen bond. We compared the calculated positions of the resonances with the electron transmission spectroscopy data measured by Modelli et al. [J. Phys. Chem. A 115, 10775 (2011)]. In general the agreement between theory and experiment is good. In particular, our results show the existence of a π* temporary anion state of A2 symmetry for all three halopyrimidines, in agreement with the dissociative electron attachment spectra also reported by Modelli et al. [J. Phys. Chem. A 115, 10775 (2011)].
我们报告了低能电子与卤代嘧啶（即 2-氯、2-溴和 5-溴嘧啶）弹性碰撞的计算截面。我们采用 Schwinger 多通道方法和赝势，在静态交换和静态交换加极化近似水平下计算了能量高达 10 eV 的截面。我们发现每个分子都有四个形状共振：三个位于环上的π性质，一个位于碳卤键上的σ性质。我们将计算出的共振位置与 Modelli 等人测量的电子传输光谱数据进行了比较[J. Phys. Chem. A 115, 10775 (2011)]。总的来说，理论和实验之间的一致性很好。特别是，我们的结果表明，所有三种卤代嘧啶都存在 A2 对称的π*临时阴离子态，这与 Modelli 等人也报道的电子离解谱[J. Phys. Chem. A 115, 10775 (2011)]一致。
