Gas phase anion photoelectron spectroscopy and theoretical investigation of gold acetylide species

Abstract

We conducted gas phase anion photoelectron spectroscopy and density functional theory studies on a number of gold acetylide species, such as AuCH, AuCAu, and AuCH. Based on the photoelectron spectra, the electron affinities of AuCH, AuCAu, and AuCH are measured to be 1.54(±0.04), 1.60(±0.08), and 4.23(±0.08) eV, respectively. The highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of AuCH and AuCAu are measured to be about 2.62 and 2.48 eV, respectively. It is interesting that photoelectron spectra of AuCH and AuCAu display similar spectral features. The comparison of experimental and theoretical results confirms that the ground-state structures of AuCH, AuCAu, and their neutrals are all linear with Au-C≡C-H and Au-C≡C-Au configurations. The similar geometric structures, spectral features, HOMO-LUMO gaps, and chemical bonding between AuCH and AuCAu demonstrate that Au atom behaves like H atom in these species. The photoelectron spectrum of AuCH shows that AuCH has a high electron affinity of 4.23(±0.08) eV, indicating AuCH is a superhalogen. Further, we found an unusual similarity between the terminal Au atom of AuCH and the iodine atom of IAuCH.

Probing the structures and bonding of auropolyynes, Au—(C≡C)n—Au− (n = 1–3), using high-resolution photoelectron imaging

“…As a comparison, we have investigated a series of AuC 2n − and AuC 2n H − species 24,25 using high-resolution PES based on a velocity-map imaging (VMI) instrument 26 and confirmed the strong influence of the auxiliary ligand on the Au− −C bonds in LAuCCH − . A similar study on AuC 4 H − , 27 as well AuC 2 H − and Au 2 C 2 − , 28 has recently been reported at lower resolution.…”

Spectroscopic Identification of the Dinitrogen Fixation and Activation by Metal Carbide Cluster Anions PtCn– (n = 4–6)

“…In this way, the ADE value of PtC n – and PtC n N 2 – ( n = 4–6) is evaluated to be 3.34 ± 0.07 (PtC 4 – ), 2.53 ± 0.11 (PtC 5 – ), 3.65 ± 0.05 (PtC 6 – ), 3.67 ± 0.05 (PtC 4 N 2 – ), 2.80 ± 0.09 (PtC 5 N 2 – ), and 3.93 ± 0.04 eV (PtC 6 N 2 – ) (Table ), respectively. Interestingly, a larger gap between the ground state peak and the excited state peak was observed in the spectra of PtC 5 – and PtC 5 N 2 – as compared with other species, indicating that the PtC 5 and PtC 5 N 2 neutrals have a large gap between their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital. − …”

Iridium Dimer Anion-Mediated C≡C Triple Bond Cleavage and Successive Dehydrogenation of Acetylene in the Gas Phase

“…The photoelectron spectra were calibrated using the known spectrum of [Au] − . 67 The energy resolution was better than 5%, corresponding to 50 meV at an electron kinetic energy of 1 eV.…”

“…The photoelectrons are detected by a microchannel plate/phosphor screen combination, and the photoelectron images are collected by a charge-coupled device camera. The photoelectron spectra were calibrated using the known spectrum of [Au] − . The energy resolution was better than 5%, corresponding to 50 meV at an electron kinetic energy of 1 eV.…”