Photoelectron Spectroscopic and Theoretical Study of Aromatics—Pb_m Anionic Complexes (Aromatics = C6H5, C5H4N, C4H3O, and C4H4N; m = 1-4): A Comparative Study

摘要

The reactions between lead vapored 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 adiabatic electron affinities (EAs) of the dominant anionic products Pb_mC6H_5~-, Pb_mC5H4N~- (m = 1-4) and Pb_mC4H3O~-, Pb_mC4H4N~- (m = 1-3) dehydrogenated complexes are obtained from the photoelectron spectra with 308 and 193 nm photon, respectively. It is found that the EAs of Pb_mC4H4N are higher than those of Pb_mC6H5, Pb_mC5H4N, and Pb_mC4H3O with the same metal number m. The possible structures for Pb_mC4H4N~- complexes were calculated with density functional theory (DFT) and the most stable structure was confirmed. The adiabatic detachment energies for the most stable structure were in agreement with the experimental PES results. The calculated density of state (DOS) agrees with the experimental PES spectrum well. It was confirmed by the theoretical calculations that the C4H4N group bonds on lead clusters through the Pb—N σ bond.