Showing papers by "Lester Andrews published in 1977"
67 citations
TL;DR: The coaxial orifice discharge tube is an effective windowless resonance lamp for argon and neon photolysis of matrix-isolated molecules as discussed by the authors, which has been shown to increase yields of CCl3 and CCl2.
Abstract: Experiments have shown that the coaxial orifice discharge tube is an effective windowless resonance lamp for argon and neon photolysis of matrix‐isolated molecules. Argon resonance photoionization of CCl4 produced CCl+3 at 1037 cm−1, which photolyzed with intense visible light. Discharged noble gas mixtures produced increased yields of CCl3 and CCl2 and new bands sensitive to near‐infrared photolysis, which are assigned to the weakly‐bound species CCl+3–Cl, CCl2–Cl+2, and Cl+3. Krypton resonance photoionization of CBr4 gave CBr+3 at 874 cm−1, which also decreased with intense mercury arc photolysis.
57 citations
Abstract: Mg, Ca, and Sr atoms were codeposited with argon and krypton at 10 K for optical absorption investigation of the van der Waals diatomic molecules. Very strong and weak structured absorptions were observed for Mg2 at 367 and 444 nm, respectively. An unstructured 507 nm and a strong structured 648 nm absorption were found for Ca2, and a strong structured 710 nm absorption was observed for Sr2. Intermediate absorptions with intermediate spacings were observed for CaMg, SrMg, and SrCa in mixed‐metal experiments. The strong absorptions are assigned to 1Σ+u(1S+1P) ←1Σ+g(1S+1S) transitions.
56 citations
TL;DR: The vibration and pure rotational Ramaman spectra of H2, D2, and HD were observed in argon, krypton, xenon, nitrogen, and oxygen matrices at 12 K as discussed by the authors.
Abstract: The vibration–rotational and pure rotational laser–Raman spectra of H2, D2, and HD were observed in argon, krypton, xenon, nitrogen, and oxygen matrices at 12 K. Transitions arising from the J=0 and J=1 rotational levels were seen for H2 and D2, but from only the J=0 level for HD. Only transitions from the J=0 level were observed for H2 in an oxygen matrix. It is interesting that hydrogen is trapped at all in an inert gas matrix at 12 K; this indicates that hydrogen molecule–inert gas atom interactions are stronger than hydrogen–hydrogen interactions.
32 citations
TL;DR: In this article, the most intense absorption was due to the 1 P 1 ← 1 S 0 atomic transition, and a weak band is due to 3 P 1 − 1 S − 0 atomic absorption.
31 citations
TL;DR: In this paper, a structure band at 666 nm with 117 ± 2 cm − spacings was identified and the band origin at 14 432 ± 4 cm −1, where the transition 1 ∑ + u (1 S + 1 P) ← 1∑ + g ( 1 S+ 1 S) and the bonding in ground and excited Ca 2 states fit a simple molecular orbital model.
23 citations
TL;DR: In this article, it was shown that a strong band at 1244 cm −1 is due to ν 3 of NO − 2 in the Ca + NO −2 complex.
13 citations
TL;DR: Optical and resonance Raman spectra of the reaction products of Mg, Ca, Sr, and Ba with ozone were observed in argon and nitrogen matrices as mentioned in this paper, and the visible spectra were characterized by strong, vibronically structured absorptions between 540 and 350 nm, and are assigned to the alkaline earth metal ozonides, A + O 3 − Vibrational analysis yielded ω1′ and ω 1x1 values of about 900 and 6 cm−1, respectively, with only slight variation from metal to metal Resonance Raman Spect
12 citations
TL;DR: The products of 44 Ca atom reactions with ozone and oxygen have been isolated in solid nitrogen at 15 K as discussed by the authors, and an excellent wavenumber fit for four isotopic molecules confirms the diatomic CaO assignment.
12 citations
TL;DR: In this paper, various xenon/fluorine mixtures were photolyzed in solid argon matrices and examined in the infrared spectral region with either a Fourier transform spectrometer or with a grating spectrometers.
Abstract: Various xenon/fluorine mixtures were photolyzed in solid argon matrices and examined in the infrared spectral region with either a Fourier transform spectrometer or with a grating spectrometer. After photolysis, a strong peak was observed at 215 cm−1 in addition to the known XeF2(ν3) peak at 549 cm−1. The appearance of the same two bands in Ar matrices containing the vapors over XeF2 indicated the assignment of the 215 cm−1 band to XeF2(ν2). The fundamental of XeF was not observed either because it is masked by the XeF2(ν2) peak or because it has a small infrared absorption coefficient.
12 citations
TL;DR: In this paper, MCD measurements on XeF, XeCl and XeI matrix isolated in Ar at low temperature are reported. And some relationships among the various spectroscopic parameters are established by combining these data existing absorption and ESR measurements.