期刊
JOURNAL OF PHYSICAL CHEMISTRY A
卷 119, 期 33, 页码 8832-8845出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpca.5b05672
关键词
-
资金
- National Science Foundation [CBET-1336105]
- Defense Threat Reduction Agency (DTRA) [HDTRA1-14-1-0008]
- European Union [FP7-PEOPLE-2013-CIG-NEWLIGHT]
- Leverhulme Trust [RPG-2013-365]
- Directorate For Engineering
- Div Of Chem, Bioeng, Env, & Transp Sys [1336105] Funding Source: National Science Foundation
All stages of the electrocyclic ring-opening of 1,3-cyclohexadiene (CHD) were observed by time-resolved photoionization-photoelectron spectroscopy. Spectra of the 1B state, previously unobserved using time-resolved methods, were obtained upon optical excitation using ultrashort laser pulses at 4.60 or 4.65 eV, followed by ionization with pulses at 3.81, 3.85, and 4.10 eV, revealing a 1B lifetime of 30 fs. In an experiment using 3.07 eV probe photons and a 4.69 eV pump, we observed a time-sequenced progression of Rydberg states that includes s, p, and d states of the series n = 3 to 6. The sequentiality of the Rydberg signals points to an ionization mechanism that captures the molecule on different points along the reaction path in 2A. A dynamic fit of the Rydberg signals, coupled with MS-CASPT2 calculations, reveals that as the wavepacket moves down the potential energy surface it acquires kinetic energy at a rate of 28 eV/ps before reaching the conical intersection to the 1A ground state. During the reaction, the terminal carbon atoms separate at a speed of 16 angstrom/ps. A deconvolution of the Rydberg signals from a broad feature assigned to structurally disperse 1,3,5-hexatriene (HT) shows the formation of the open-chain hexatriene structure with an onset 142 fs after the initial absorption of a pump photon. The experimental observations are discussed in the context of recent ultrafast X-ray scattering experiments and theoretical quantum dynamics simulations.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据