Showing papers by "Richard J. Saykally published in 1985"
122 citations
TL;DR: In this paper, the results of an extensive study of the ν3 (asymmetric stretch) vibration of the H3O+ ion were reported, and a total of 86 and 41 transitions were measured with a precision of 0.002 cm−1 for the s−s and a−a inversion subbands, respectively, and least squares fit to an accurate Hamiltonian.
Abstract: The results of an extensive study of the ν3 (asymmetric stretch) vibration of the H3O+ ion are reported. A total of 86 and 41 transitions were measured with a precision of 0.002 cm−1 for the s–s and a–a inversion subbands, respectively, and least‐squares fit to an accurate Hamiltonian. Twenty‐four parameters were determined in the analysis. The ν3 frequencies are 3535.974(11) and 3519.397(25) cm−1 for the s–s and a–a inversion components, respectively.
80 citations
TL;DR: In this article, the rotational state-dependent linewidths for CO+ in low-pressure plasmas were revealed, while translational temperatures in excess of rotational temperatures, and non-Boltzmann rotational distributions were observed for both of these ions in low pressure plasma environments.
17 citations
TL;DR: In this paper, the C-H stretching vibration (ν1) of HCS+ was measured near 3.2 μm with a color center laser by the velocity modulation technique in a He/CO/H2S plasma.
Abstract: The measurement and analysis of the C–H stretching vibration (ν1) of HCS+ is reported. Eighty transitions [R(0)–R(44), P(1)–P(35)] were measured near 3.2 μm with a color center laser by the velocity modulation technique in a He/CO/H2S plasma. The ν1 band origin is at 3141.6823(5) cm−1, in excellent agreement with the ab initio prediction of Botschwina and Sebald.
13 citations
01 Jan 1985
TL;DR: The early qualitative versions of Solomon and Klemperer1 and Herst et al.2 which first predicted the preeminence of ion-molecular reactions in these cold, diffuse environments, are now supplanted by the modern sophisticated computer models of Mitchell, Ginzberg and Kuntz, as mentioned in this paper.
Abstract: Over the last decade, modeling of the chemistry occurring in interstellar gas clouds has evolved dramatically The early qualitative versions of Solomon and Klemperer1 and Herbst and Klemperer,2 which first predicted the preeminence of ion-molecular reactions in these cold, diffuse environments, are now supplanted by the modern sophisticated computer models of Mitchell, Ginzberg and Kuntz,3Prasad and Huntress4, Watson,5and others Quantitative predictions of molecular abundances are now given for an impressive number of species, including some two dozen of the most important molecular ions In Table 1, the molecular ions expected to be most abundant in cold (50°K), dense (n≈106cm-3) clouds are listed, along with abundances (relative to H2) predicted by Mitchell, Ginzberg, and Kuntz,3appropriate for a cloud density of 106cm-3
4 citations
01 Jan 1985
TL;DR: In this paper, a new spectroscopic technique for directly measuring vibrational absorption spectra of van der Waals bonds is presented, which is used for the measurement of bending (υ2) vibration in ArHC1 near 34 cm−1.
Abstract: Molecules held together by van der Waals forces generally posess bond strengths which are ~0.1–1.0% of normal chemical bonds, i.e. 0.1–1.0 Kcal/mole (.35–350 cm−1). Such extremely weak bonds exhilgit vibrational frequencies which lie in the far-infrared, eq. 10–100 cm−1 (1000–1000). In order to measure vibration-rotation spectra of van der Waals bonds, one must devise a method which possesses very high sensitivity in this region of the spectrum, and which preferably also has very high resolution capabilities, such that the hyperfine interactions, which can provide important information on the potential surface of these clusters, can be resolved. In this paper we report the development of such a new spectroscopic technique for directly measuring vibrational absorption spectra of van der Waals bonds. In this method, van der Waals molecules are produced in a supersonic free jet expansion located inside the optical cavity of an optically pumped far infrared laser. Electric field tuning of dipole-allowed vibration-rotation transitions into coincidence with the laser frequency produces an extremely sensitive detection method which also possesses very high (~1 MHz) resolution. We shall describe this new technique and its initial application for the measurement of the bending (υ2) vibration in ArHC1 near 34 cm−1.
1 citations