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

作者：Bull James N; Verlet Jan R R^*

来源：Physical Chemistry Chemical Physics, 2017, 19(39): 26589-26595.

DOI：10.1039/c7cp03628k

Frequency-resolved photoelectron spectroscopy applied to mass-selected cluster anions is an insightful approach to characterise the dynamics of pi*-resonances with microsolvation. Here, the technique is demonstrated with monomer, dimer and trimer radical anions of para-toluquinone (pTQ) over a similar to 1 eV excitation window above the detachment threshold. The pTQ(-) spectra show similar resonances and dynamics to para-benzoquinone, a prototype electrophore. The dimer, (pTQ)(2)(-), has a pi-stacked geometry and shows a competition between photodissociation and prompt autodetachment. The trimer, (pTQ)(3)(-), also has a pi-stacked cluster geometry and shows vibrational autodetachment from a non-valence state up to similar to 0.7 eV above-threshold, outcompeting dissociation. At higher photoexcitation energies, (pTQ)(3)(-) shows monomer-like dynamics, blue-shifted in photoexcitation energy by the cluster cohesion energy. Overall, the study highlights the variety of non-adiabatic dynamics available to pi*-resonances and the profound changes that occur through clusterization with one and two monomers.

• 出版日期2017-10-21