Picosecond time-resolved photoelectron spectroscopy as a means of gaining insight into mechanisms of intramolecular vibrational energy redistribution in excited states

Abstract

We consider the information that can be obtained from time-resolved photoelectron spectroscopy studies of intramolecular vibrational energy redistribution (IVR) in excited states of molecules, focusing on picosecond time-resolved studies of IVR in the intermediate regime. We show that time-resolved measurements may tell us as much about the experimental conditions as they do about the dynamics under examination. We show that carefully controlled picosecond time-resolved photoelectron studies are becoming feasible and that these, combined with robust calculations of Franck-Condon factors, may point the way forward in the quest to understand excited state IVR.

Excited states of multiply-charged anions probed by photoelectron imaging: riding the repulsive Coulomb barrier

“…Additionally, the PE angular 5 distribution from monoanion photodetachment is governed by the interference of the outgoing partial waves and requires knowledge of the phase and cross-section into each channel. 73,74 Hence, a direct comparison between the dianion and anion must be done with great care. An alternative method was developed in 10 our group which employs a well-defined transition to align (in one dimension) an MCA before detachment.…”

“…Quantum mechanically, a PE wave is composed of partial 50 waves which interfere to produce the asymptotic PE angular distribution commonly observed in anions or neutrals. 73 In MCAs, it appears that this inherent anisotropy is trumped by the influence of the RCB and classical mechanics dominates. That is not to say that all interference is lost and we anticipate that, under 55 the right conditions, quantum effects should be observable.…”

Cross sections and photoelectron angular distributions in photodetachment from negative ions using equation-of-motion coupled-cluster Dyson orbitals

“…[1][2][3][4][5][6][7][8][9] Kinetic energy distribution of photoelectrons contains information about electronic and vibrational levels, which, in turn, depend on the potential energy surfaces ͑PESs͒ of the species involved. The analysis of Franck-Condon progressions allows one to determine structural differences between the initial and ionized/ detached states, as well as to infer changes in the electronic wave functions.…”

Nuclear motion captured by the slow electron velocity imaging technique in the tunnelling predissociation of the S1 methylamine

“…12,13 Because of this advantage, SEVI is being actively used in the investigation of the transition state of bimolecular reactions 14 or the intramolecular vibrational state redistribution process. 15 In this work, SEVI is employed for the study of predissociation dynamics of methylamines on the first electronically excited state. Energy and angular distributions of photoelectron from the ionization of predissociating molecule give the essential information about the complicated nature of the reaction path along which the chemical bond breaking event takes place via tunnelling.…”