Rotational branching ratios at low photoelectron energies in resonant enhanced multiphoton ionization of NO

Journal Article · Tue Feb 28 23:00:00 EST 1989 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.455953· OSTI ID:6532830

Rudolph, H; McKoy, V; Dixit, S N

We report calculated rotational branching ratios for very low energy (50 meV) photoelectrons resulting from (1+1') resonant enhanced multiphoton ionization (REMPI) via the J/sub i/ = 1/2, 3/2, 5/2, and 7/2 levels of the P/sub 11/ branch of the A /sup 2/..sigma../sup +/ (3ssigma) state of NO. Even angular momentum transfer (..delta..NequivalentN/sub +/-N/sub i/) peaks are dominant in these rotational distributions, in agreement with the selection rule ..delta..N+l = odd. Angular momentum coupling in the photoelectron wave function arising from the molecular ion potential leads to smaller but appreciable ..delta..N = odd peaks. The calculated ..delta..N = 0 to ..delta..N = +2 peak ratios show the same strong decrease when J/sub i/ increases from 1/2 to 3/2 as seen in the experimental zero-kinetic-energy (ZEKE) photoelectron spectra (Sander et al., Phys. Rev. A 36, 4543 (1987)), but do not show the rapid die-off of the ..delta..Nnot =0 peaks for higher J/sub i/ observed experimentally. The calculated trend in the ..delta..N = +2 vs ..delta..N = 0 peaks could be understood on the basis of simple angular momentum transfer arguments. These same arguments indicate that this trend in the ..delta..N = 0 and +2 peaks with increasing angular momentum is not generally expected in other branches. Spectra via the R/sub 21/ ( J) branch are presented to support this assertion. We also present photoelectron angular distributions which show a strong dependence on ..delta..N reflecting the changing composition of the photoelectron wave function.

• Research Organization: Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125
• OSTI ID: 6532830
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 90:5; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BRANCHING RATIO
CHALCOGENIDES
ELECTRON SPECTROSCOPY
ENERGY LEVELS
EXCITED STATES
IONIZATION
MULTI-PHOTON PROCESSES
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
ROTATIONAL STATES
SPECTROSCOPY