Dynamics of π*-resonances in anionic clusters of para-toluquinone

Abstract

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Photoelectron spectroscopy of para-benzoquinone cluster anions

“…The VDE of pBQwas computed to be 2. dimer, the hydrogen-bonded monomer buckles out of the plane of the quinone ring, as also previously noted in the (pTQ)3study. 37 The calculated VDE of the trimer is 3.08 eV and has been included in Figure 2.…”

“…Our group has also studied clusters of para-toluquinone (pTQ)n -(n ≤ 3) by 2D photoelectron spectroscopy. 37 This showed some indirect evidence that the dimer dissociated above threshold, while the trimer revealed interesting valence to non-valence internal conversion dynamics near threshold, in which the non-valence state observed presented the first example of a predominantly correlation-bound state. 38 While pTQ can be viewed as a good approximation to pBQ, we were previously not able to produce pBQ cluster anions in the electrospray source.…”

Evidence of Electron Capture of an Outgoing Photoelectron Wave by a Nonvalence State in (C6F6)n–

“…Finally, we compare the present work with studies in para-toluquinone anionic clusters (pTQ)n − , 7,20 and the iodide-solvent clusters: I − (Xe)n and I − (H2O)n clusters. [41][42][43][44][45] In (pTQ)n − , the electron is similarly localized on a single pTQ that is solvated by neutral pTQ molecules, similar to the (C6F6)n − case.…”

“…[41][42][43][44][45] In (pTQ)n − , the electron is similarly localized on a single pTQ that is solvated by neutral pTQ molecules, similar to the (C6F6)n − case. While (pTQ)2 − showed evidence for dissociation, 20 time-resolved PE spectroscopy of (pTQ)3 − also showed the formation of a non-valence state. 7 However, the dynamics in this cluster were interpreted in terms of an internal conversion from an initially photoexcited π* resonance into a non-valence state of the cluster.…”

“…18,19 It is thought that these delocalized states are related on a molecular level to the non-valence correlation-bound state of C6F6 − . 10 To gain additional insight into the electronic states and electron injection into C6F6 and to attempt to bridge the gap between the single molecule and condensed phase observations, we present a frequency-resolved (2D) photoelectron (PE) imaging study [20][21][22] of anionic hexafluorobenzene clusters, (C6F6)n − with n = 1-5. The PE spectra show evidence of s-wave electron capture of the outgoing electron wave, while for an outgoing p-wave, such capture is not seen.…”