Electron delocalisation in conjugated sulfur heterocycles probed by resonant Auger spectroscopy

Abstract

We propose a novel approach for an indirect probing of conjugation and hyperconjugation in core-excited molecules using resonant Auger spectroscopy. Our work demonstrates that the changes in the electronic structure...

Disentangling the resonant Auger spectra of ozone: overlapping core-hole states and core-excited state dynamics

“…In the past few years, Auger spectroscopy has been extensively used in connection to X-ray absorption spectroscopy (XAS) and/or X-ray photoelectron spectroscopy (XPS) to probe site-specificity in molecular photofragmentation. 25–29 Because of their high sensitivity to electronic and nuclear dynamics, AES/RAES are becoming increasingly popular techniques to unravel underlying electronic structure, 30 and nuclear dynamics of photoexcited molecules. 31–35…”

“…In the past few years, Auger spectroscopy has been extensively used in connection to X-ray absorption spectroscopy (XAS) and/or X-ray photoelectron spectroscopy (XPS) to probe sitespecificity in molecular photofragmentation. [25][26][27][28][29] Because of their high sensitivity to electronic and nuclear dynamics, AES/ RAES are becoming increasingly popular techniques to unravel underlying electronic structure, 30 and nuclear dynamics of photoexcited molecules. [31][32][33][34][35] RAES measurements of ozone have been obtained with photon energies of 530.8 and 536.7 eV, which correspond to the 1s O Tp*(2b 1 ) and 1s O Ts*(7a 1 ) excitations, 12,13 and at 542.3 eV, that lies near the 1s O Cs*(7a 1 ) excited state and above the 1s O T À1 ionization threshold.…”

X-ray induced ultrafast charge transfer in thiophene-based conjugated polymers controlled by core-hole clock spectroscopy

“…This counter-intuitive behaviour has been recently observed in gas-phase thiophene. 38 It was demonstrated that in the process of core-excitation and Auger decay, the energy order of the first two core-excited states and the corresponding final states reverses due to the destabilisation of the conjugated π-system in the aromatic molecules. The presence of the same effect in gas-phase thiophene and solid-state thiophene-based polymers points at the general nature of the observed phenomenon for conjugated systems.…”

Charge Transfer in the P(g42T-T):BBL Organic Polymer Heterojunction Measured with Core-Hole Clock Spectroscopy

“…The main peak, labeled A, consists of two peaks lying close to each other at 2477.1 eV (A1) and 2477.8 eV (A2). Peak A1 at a lower energy is assigned to the S 1s → π*­(S–C) transition and A2 is assigned to the S 1s → σ*­(S–C) transition. ,− These peaks display large differences in intensity for different angles ϕ, suggesting ordering of the sulfur-containing donor polymer. More precisely, they exhibit the opposite trend when the X-ray absorption is measured with normal and grazing incidence, which is expected for π* and σ* molecular orbitals.…”