Probing intramolecular vibronic coupling through vibronic-state imaging

Vibronic coupling is a central issue in molecular spectroscopy. Here we investigate vibronic coupling within a single pentacene molecule in real space by imaging the spatial distribution of single-molecule electroluminescence via highly localized excitation of tunneling electrons in a controlled plasmonic junction. The observed two-spot orientation for certain vibronic-state imaging is found to be evidently different from the purely electronic 0–0 transition, rotated by 90°, which reflects the change in the transition dipole orientation from along the molecular short axis to the long axis. Such a change reveals the occurrence of strong vibronic coupling associated with a large Herzberg–Teller contribution, going beyond the conventional Franck–Condon picture. The emergence of large vibration-induced transition charges oscillating along the long axis is found to originate from the strong dynamic perturbation of the anti-symmetric vibration on those carbon atoms with large transition density populations during electronic transitions.

High resolution vibronic state-specific dissociation of NO2+ in the 10.0–15.5 eV energy range by synchrotron double imaging photoelectron photoion coincidence

Low-lying electronic states of NO2+ are prepared with vibrational structures and their state-specific dissociation mechanisms are unraveled with high-resolution i2PEPICO.

Experimental observation of nonadiabatic bifurcation dynamics at resonances in the continuum

In the strong vibronic state mixing regime, both Herzberg type-I and type-II predissociations coexist and proceed in a competitive way.

A very rapid electronic relaxation process in a highly conjugated Zn(ii)porphyrin–[26]hexaphyrin–Zn(ii)porphyrin hybrid tape

We demonstrate that the electronic deactivation overtakes the vibrational relaxation processes in the energy relaxation processes from the initially excited vibronic state manifolds in highly conjugated molecular systems.