Vibronic fine structure in the nitrogen 1s photoelectron spectra from Franck-Condon simulations II: Indoles
arXiv:2307.01510 · doi:10.1103/PhysRevA.108.022816
Abstract
The vibronic coupling effect in nitrogen 1s X-ray photoelectron spectra (XPS) was systematically studied for a family of 17 bicyclic indole molecules by combining Franck-Condon simulations (including the Duschinsky rotation effect) and density functional theory. The simulated vibrationally-resolved spectra of 4 molecules agree well with available experiments. Reliable predictions for this family further allowed us to summarize rules for spectral evolution in response to three types of common structural changes (side chain substitution, CHN replacement, and isomerization). Interestingly, vibronic properties of amine and imine nitrogen are clearly separated: they show negative and positive ZPE (zero-point vibration energy of the core-ionized with respect to the ground state), respectively, indicating flatter and steeper PESs induced by the N 1s ionization; amine N's show stronger mode mixing effects than imine N's; the 1s ionizations on two types of nitrogens led to distinct changes in local bond lengths and angles. The rules are useful for a basic understanding of vibronic coupling in this family, and the precise spectra are useful for future reference and data mining studies.
References in corpus (1)
Cited by in corpus (4)
- Vibronic fine structure in the nitrogen 1s photoelectron spectra from Franck-Condon simulations. III. Rules for amine/imine N atoms in small N-heterocycles
- Temperature and Tautomeric Effects in High-Resolution Oxygen 1s X-ray Photoelectron Spectroscopy of Purines and Pyrimidines
- Franck-Condon Simulation of Vibrationally-Resolved X-ray Spectra for Diatomic Systems: Validation of Harmonic Approximation and Density Functional Theory
- Simulating Vibrationally-Resolved X-ray Photoelectron Spectra of Flexible Molecules: Linear Alkanes CH (=1-8)