Absorption coefficients of sulfur dioxide in the spectral region 1050-2170 A were measured photoelectrically at about 500 points of the spectrum. The absorption spectrum below 1350 A is interpreted in terms of a Rydberg series converging upon the ionization potential of 12.34 ev obtained by the photoionization method.
The absorption intensities of SO2 were measured in the wavelength region 1849–3150 Å employing the hydrogen continuum as the source and at selected wavelengths utilizing the mercury line spectrum. The pressure dependence of the absorption intensity was investigated at 1849, 2537, and 3131 Å. The existence of an absorption continuum commencing at 2280 Å has been established and attributed to the dissociation of SO2 forming SO and a ground-state oxygen atom. The onset of the continuum provides an upper limit value to the dissociation energy of SO2. The implications upon the SO2 and SO dissociation energies are discussed.
Absorption and photo-ionization cross sections of O2 were measured at a number of wavelengths primarily in the region 850–1100 A by a photoelectric method. The Rydberg bands H, H′, M and M′ were found to be strongly pre-ionized, and vibrational structures in the underlying continuum appeared to be present. The photoionization method gave 12.08±0.01 ev as the first ionization potential of O2. This value, combined with data from emission spectra, yielded a value 6.65 ev for the dissociation energy of O2+ and 16.83 ev for the third ionization potential of O2 (O2+A2Πu←O2X 3Σg-). In the case of N2, a number of ``windows'' were observed and it was not possible to establish the presence of an absorption continuum in the region 850–1100 A.
Vacuum-ultraviolet emission from the reaction of atomic oxygen with acetylene was investigated spectrographically and with photoionization detectors. The spectrum was observed at wavelengths above 1400 Å and consisted entirely of bands belonging to the fourth positive system of CO. At short wavelengths, the intensity declines rapidly, but radiation was detected with photoionization detectors filled with xylene (1425–1475 Å), NO (1100–1340 Å), and CS2 (1100–1260 Å). The high-energy limit of the emission is, correspondingly, greater than 226 kcal/mole or almost 10 eV. The dependence of the intensity on initial reactant and third-body concentrations was investigated and compared with similar concentration-dependence data for the intensity of the CH band at 4300 Å. The results show that the vacuum-ultraviolet CO emission cannot be produced by either third-body recombination of carbon and oxygen atoms or by the reaction of atomic oxygen with excited CH radicals in the A2Δ state. The reaction proposed by Becker and Bayes O+C2O→CO (A 1Π)+CO (X 1Σ)can explain the observed emission if it is assumed that a fraction of the reaction C2O radicals are vibrationally excited.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.