Photoelectron Spectroscopic and Theoretical Study of Aromatic–Bim Anionic Complexes (Aromatic = C6H5, C5H4N, C4H3O, and C4H4N; m = 1–3): A Comparative Study

Abstract

The reactions between Bi clusters generated by laser ablation and different aromatic molecules (C6H6, C5H5N, C4H4O, or C4H5N) seeded in argon carrier gas were studied by a reflectron time-of-flight mass spectrometer (RTOF-MS) with a photoelectron spectrometer. The photoelectron (PE) spectra of the dominant anionic products Bi(m)C6H5(-), Bi(m)C5H4N(-) (m = 1-4) and Bi(m)C4H3O(-), Bi(m)C4H4N(-) (m = 1-3) dehydrogenated complexes were obtained by 308 and 193 nm laser, respectively. It was found that the adiabatic electron affinities (EAs) of Bi(m)C4H4N are higher than those of Bi(m)C6H5, Bi(m)C5H4N, and Bi(m)C4H3O with the same metal number m. Theoretical calculations with density functional theory (DFT) were carried out to elucidate the possible structures for Bi(m)C4H4N(-) and Bi(m)C4H4N complexes. By comparison of the theoretical and experimental EAs, the most possible structures were the isomers in which the C4H4N group binds to metal clusters with the N-Bi bond, and their simulated spectra based on Koopmans' theorem were in correct agreement with the PES results. Furthermore, the analysis of the molecular orbital composition provided evidence that the C4H4N group contributes a single electron to bind to Bi(m) clusters with the Bi-N σ bond.