Bowen M Shane, Becucci Maurizio, Continetti Robert E
Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0340, USA.
J Chem Phys. 2006 Oct 7;125(13):133309. doi: 10.1063/1.2210010.
The photodetachment dynamics of the iodide-aniline cluster, I-(C6H5NH2), were investigated using photoelectron-photofragment coincidence spectroscopy at several photon energies between 3.60 and 4.82 eV in concert with density functional theory calculations. Direct photodetachment from the solvated I- chromophore and a wavelength-independent autodetachment process were observed. Autodetachment is attributed to a charge-transfer-to-solvent reaction in which incipient continuum electrons photodetached from I- are temporarily captured by the nascent neutral iodine-aniline cluster configured in the anion geometry. Subsequent dissociation of the neutral cluster removes the stabilization, leading to autodetachment of the excess electron. The dependence of the dissociative photodetachment (DPD) and autodetachment dynamics on the final spin-orbit electronic state of the iodine fragment is characterized. The dissociation dynamics of the neutral fragments correlated with autodetached electrons were found to be identical to the DPD dynamics of the I atom product spin-orbit state closest to threshold at a given photon energy, lending support to the proposed sequential mechanism.
利用光电子-光碎片符合光谱技术,在3.60至4.82电子伏特的几个光子能量下,结合密度泛函理论计算,研究了碘化物-苯胺簇I-(C6H5NH2)的光剥离动力学。观察到从溶剂化的I-发色团的直接光剥离和一个与波长无关的自剥离过程。自剥离归因于电荷转移到溶剂的反应,其中从I-光剥离的初始连续电子被配置为阴离子几何结构的新生中性碘-苯胺簇暂时捕获。随后中性簇的解离消除了这种稳定作用,导致多余电子的自剥离。表征了解离光剥离(DPD)和自剥离动力学对碘碎片最终自旋轨道电子态的依赖性。发现与自剥离电子相关的中性碎片的解离动力学与给定光子能量下最接近阈值的I原子产物自旋轨道态的DPD动力学相同,这为所提出的顺序机制提供了支持。