92 research outputs found
Is phenyl a good migrating group in the rearrangement of organoborates generated from sulfur ylides?
HIGH-RESOLUTION STIMULATED RAMAN SPECTROSCOPY OF THE BAND OF
1. A Owyoung, C. W. Patterson, and R. S. McDowell, Chem. Phys. Lett. 59, 156 (1978). 2. R. S. McDowell, C. W. Patterson, and A. Owyoung, J. Chem. Phys., in press. 3. A. Cabana, D. L. Gray, A. G. Robiette, and G. Pierre, Mo1. Phys. 36, 1503 (1978)Author Institution:A Doppler-limited isotropic Raman spectrum of the symmetric stretching fundamental of has been recorded using high-sensitivity “quasi-cw” inverse Raman spectroscopy. Unlike the corresponding fundamentals of (1) and (2), this band exhibits compact non-overlapping J manifolds that extend over about . Since and the infrared-active stretch reported by Cabana et al. (3) and the Raman frequencies of Q (0) through Q(14). The results confirm the infrared analysis (3), in which several perturbation-allowed transitions were identified in absorption, but the molecular constants are much better determined by the inclusion of the Raman data. Significant intensity perturbations occur at higher J due to a break down of the selection rule (N is the index distinguishing between levels of the same J and rovibrational symmetry), and have been quantitatively accounted for
VIBRATIONAL ANHARMONICITY OF IN CRYOGENIC SOLUTION
V.V. Bertsev, T.D. Kolomiitseva, and N.M. Tsyganenko, Opt. Spectrosc. 37, 263 (1974). S.R.J. Brueck, to be published. Experimental work supported by the Department of the Air Force.Author Institution:The infrared spectrum of has been recorded in liquid and liquid solutions. The suppression of rotational structure and the elimination of hot bands at low temperature give estimates of band origins that could only be achieved in the gas phase by detailed high-resolution analyses of each hand. A normal coordinate anharmonic force field has been fitted directly to fundamental, overtone and combination bands of the cryogenic solution spectra. It will be shown that at least for the derived anharmonic constants are in good agreement with those obtained from gas phase data (and force fields based upon gas phase data), despite appreciable shifts in the fundamentals from gas to cryogenic solution
INFRARED ABSORPTION LINE ASSIGNMENTS AND STRENGTHS FOR THE BAND OF METHANE
Author Institution:A resolution study of the absorption line strengths of methane in the 3.3 region at both room and reduced temperatures reveals over 200 lines with strengths between and at 296 K which belong to the band. Most of these lines can be assigned with the aid of combination differences, experimental values for and a preliminary energy level calculation
LINE ASSIGNMENTS AND INTENSITIES FOR THE BAND OF METHANE
Author Institution: Jet Propulsion Laboratory; Department of Physics, Florida State University; Department of Chemistry, The University, Whiteknights, ReadingThe forbidden transitions have been identified and allowed transitions assignments extended for the band of using spectra recorded at resolution with the four-pass grating spectrometer at Florida State University. The assignment process has been greatly aided by the measurement of individual line strengths at different temperatures to obtain experimental values for the ground state energy levels of the transitions. Corresponding allowed transitions of of have been identified
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The infra-red spectra of silyl fluoride and silyl fluoride-d3
Infra-red spectra have been recorded for silyl fluoride and silyl fluoride-d3 at a resolution of circa 0·3 cm-1. Rotational structure has been observed for parallel fundamentals in both molecules, and for all perpendicular fundamentals. In both SiH3F and SiD3F the A1 and E species deformation modes interact strongly via a Coriolis perturbation; this has been analysed, and the band origin of v5 for SiH3F is reassigned. A hybrid-orbital force field based on the experimental data is also reported
Synthesis of Cyclic Organic Carbonates Using Atmospheric Pressure CO2 and Charge-Containing Thiourea Catalysts
Cycloadditions of epoxides with CO2 to synthesize cyclic five-membered ring organic carbonates are of broad interest from a synthetic, environmental, and green chemistry perspective, and the development of effective catalysts for these transformations is an ongoing challenge. A series of eight charge-containing thiourea salts that catalyze these reactions under mild conditions (i.e., 60 °C and atmospheric CO2 pressure) are reported. Substrate scope and mechanistic studies were also carried out, isotope effects were measured, and a reactive intermediate was isolated revealing a surprising pathway in which a thiourea catalyst serves as a nucleophile in the cleavage of the epoxide ring
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