Molecular beam photoionization study of carbon disulfide, carbon disulfide dimer and clusters

Journal Article · Mon Sep 15 04:00:00 EDT 1980 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.440486· OSTI ID:5123236

Ono, Y; Linn, S H; Prest, H F; Gress, M E; Ng, C Y

A new molecular beam photoionization mass spectrometer which is significantly superior to previous similar instruments in both wavelength resolution and ion intensity is described. Photoionization efficiency (PIE) data for CS/sub 2//sup +/ near the threshold (1210--1232 and 1075--1130 A) were obtained with a resolution of 0.14 A (FWHM). Rydberg series I, n=16--24, which converges to the spin--orbit excited state, /sup 2/Pi/sub 1/2/, of CS/sub 2//sup +/ was resolved on the first vibrational step in the PIE data. Observation of the autoionization resonance, series I (n=16), indicates that the value for the first ionization energy (I.E.) for CS/sub 2/ obtained in previous absorption experiments (Ref. 23) is too high. The I.E.'s for the /sup 2/Pi/sub 3/2/ and /sup 2/Pi/sub 1/2/ states of CS/sub 2/ were determined to be 10.0685 +- 0.0020 and 10.1230 +- 0.0020 eV, respectively. PIE data for (CS/sub 2/)/sub n//sup +/ with n ranging from 2 to 5 have been obtained in the wavelength region from 650 to 1350 A with this apparatus. The observed I.E.'s for (CS/sub 2/)/sub 2/, (CS/sub 2/)/sub 3/, (CS/sub 2/)/sub 4/, and (CS/sub 2/)/sub 5/ are 9.36 +- 0.02, 9.22 +- 0.02, 9.10 +- 0.02, and 9.04 +- 0.02 eV, respectively. From the measured ionization energy, and the estimated dissociation energy (0.05 eV) of (CS/sub 2/)/sub 2/, the binding energy for CS/sub 2//sup +/xCS/sub 2/ is deduced to be 17.5 +- 1 kcal/mol. This is in agreement with the value obtained previously in a high pressure mass spectrometry experiment. The Rydberg series for CS/sub 2/, which are manifested as autoionization lines in the PIE data for (CS/sub 2/)/sub 2//sup +/ in the region 850--960 A, are red shifted in energy by approx.0.075 eV for Rydberg series III and approx.0.14 eV for Rydberg series IV. Adapting the most recent assignment of Rydberg series III and IV by Larzilliere et al. symmetry arguments support a linear or near linear geometry for the carbon disulfide dimer.

• Research Organization: Ames Laboratory, U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011
• OSTI ID: 5123236
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:6; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
AUTOIONIZATION
BEAMS
CARBON COMPOUNDS
CARBON SULFIDES
CHALCOGENIDES
DIMERS
DISSOCIATION ENERGY
ENERGY
IONIZATION
MASS SPECTROSCOPY
MOLECULAR BEAMS
PHOTOIONIZATION
SPECTROSCOPY
SULFIDES
SULFUR COMPOUNDS