报告题目：Electrospray Photoelectron Spectroscopy: From Multiply Charged Anions to Ultracold Anions

报 告 人：Lai-Sheng Wang （Brown University, USA）

报告时间：2014年12月29日16:00

报告地点：物理系理科楼B315

报告摘要：We integrated an electrospray ionization source with photodetachment photoelectron spectroscopy, which has allowed any negatively charged ions present in solution to be investigated in the gas phase, including multiply charged anions, simple organic and inorganic anions to biological molecules. In this talk, I will briefly review our early effort in the studies of multiply charged anions using photoelectron spectroscopy, followed by our development of a cryogenic ion trap to create vibrationally cold anions. Cold anions are important to obtain high-resolution photoelectron spectra free of vibrational hot bands. I will also discuss our photoelectron imaging studies of multiply charged anions to probe the influence of intramolecular electrostatic effects on the photoemission angular distributions. Finally, I will discuss our very recent effort in high resolution photoelectron imaging of ultracold anions using a tunable laser, leading to the observations of dipole-bound excited states and vibrational autodetachment. I will discuss the potential to develop this experiment into a new method for vibrational spectroscopy of dipolar radicals. I will also present unexpected autodetachment dynamics via the dipole-bound states that result in excitations of forbidden molecular vibrations.