Photofragment imaging and electronic spectroscopy of Al2+
- Univ. of Massachusetts Amherst, Amherst, MA (United States)
A combination of photodissociation spectroscopy, ion imaging, and high-level theory is employed to refine the bond strength of the aluminum dimer cation (Al2+) and elucidate the electronic structure and photodissociation dynamics between 38 500 and 42 000 cm–1. Above 40 400 cm–1, structured photodissociation is observed from an extremely anharmonic excited state, which calculations identify as the double minimum G 2Σ+u state. The photodissociation spectrum of the G 2Σ+u ← X 2Σ+g transition in Al2+ gives an average vibrational spacing of 170 cm–1 for the G 2Σ+u state and ν0 = 172 cm–1 for the ground state. Photofragment images of G 2Σ+u ← X 2Σ+g transitions indicate that once the Al (4P) + Al+ (1S) product channel is energetically accessible, it dominates the lower energy, spin-allowed pathways despite being spin-forbidden. This is explained by a proposed competition between radiative and non-radiative decay pathways from the G 2Σ+u state. Here, the photofragment images also yield D0 (Al+–Al) = 136.6 ± 1.8 kJ/mol, the most precise measurement to date, highlighting the improved resolution achieved from imaging at near-threshold energies. Additionally, combining D0 (Al+–Al) with IE (Al) and IE (Al2) gives an improved neutral D0 (Al–Al) = 136.9 ± 1.8 kJ/mol.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1543866
- Journal Information:
- Journal of Chemical Physics, Vol. 148, Issue 21; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Comparison between the analysis of the asymptotic wavepacket and the associated flux for the calculation of kinetic-energy-releases function
|
journal | December 2018 |
Visible photodissociation of the CO 2 dimer cation: fast and slow dissociation dynamics in the excited state
|
journal | January 2019 |
Similar Records
Photodissociation of acetylene: Determination of D sup 0 sub 0 (HCC--H) by photofragment imaging
UV photodissociation of oxalyl chloride yields four fragments from one photon absorption