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排序方式: 共有116条查询结果,搜索用时 15 毫秒
1.
Arthur G. Maki John C. Grecu Brenda Winnewisser Manfred Winnewisser 《Journal of Molecular Spectroscopy》2003,222(2):198-212
High-resolution spectra of 15N12C12C15N and 14N13C13C14N have been measured and analyzed from 200 to 3600 cm−1. All the vibrational levels below 900 cm−1 have been observed and characterized. The Fermi resonance between ν2 and 2ν4 has been studied and the resonance constant has been determined for several cases. Several Σ− states have been directly observed for the first time for each isotopomer, the (0001111)0f, (0011111)0f, and (0002222)0f states. The pattern of the energy levels for clusters of l-type resonance coupled levels, such as 0001131,3, has been determined for cyanogen for the first time. Among other things this involved the determination of the vibrational l-type resonance constant, r45. Many of the power series constants, αi and xij, and higher order constants have been determined. 相似文献
2.
In the past few years millimeter and submillimeter wave spectroscopy has been the backbone for modern molecular line astronomy. The detection of unstable and high-temperature molecular species in the interstellar environment has stimulated the development of methods of detecting molecular ions, radicals and unstable molecules in the laboratory by means of millimeter wave technology. Some of the recent experimental advances as well as the developments which have occurred in the analysis of high resolution rotational and vibrational spectra with regard to understanding molecular dynamics will be discussed. 相似文献
3.
Guy Guelachvili K. Narahari Rao Richard H. Tipping Brenda P. Winnewisser Manfred Winnewisser 《Mikrochimica acta》1988,95(1-6):339-343
This paper reports the observation of the far infrared absorption spectrum of a single crystal of N2, measured over absorption paths of 4 cm (lengthwise) and 2 cm (across the crystal). The crystal chamber, with quartz windows, was immersed in a flow of cold helium gas. The spectrum from 20 to 120 cm–1 was recorded in the liquid phase, the-phase, and over the full temperature range of the-phase (35.6–2.0 K) with a Fourier transform spectrometer. The spectral resolution, which was not instrument-limited, and the large path allowed the observation of more detailed multiphonon-transition structure in the spectrum of the-phase than has previously been observed. 相似文献
4.
A new band with heads at 796.3.3 and 7893.1 A has been found during the flash photolysis of 3-methyl-4-oximinoisoxazol-5(411)-one. By comparison with earlier work in a neon matrix. and on the basis of a partial rotational analysis, the band is assigned as the 0 0 band of the A2x+-X211i transition of the CNO free radical. Preliminary mlecular constant are given. 相似文献
5.
6.
E. CanèL. Fusina H. BürgerW. Jerzembeck S. BrünkenF. Lewen G. Winnewisser 《Journal of Molecular Spectroscopy》2002,215(1):1-9
Infrared spectra of PD3 have been measured in the 20-320 cm−1 range and in the region of the ν2/ν4 and ν1/ν3 fundamental bands near 750 and 1690 cm−1, respectively, with a resolution of ca. 0.0025 cm−1. Furthermore, submillimeter-wave spectra covering the J=4-3, 13-12, and 14-13 clusters in the vibrational ground state were recorded. The observed ΔJ=+1 rotational lines were augmented by about 5500 ground state combination differences formed from transitions belonging to the fundamental bands. Of these, 1300 involved perturbation-allowed lines with ΔK≠0. These data and observations taken from the literature were appropriately weighted and fitted to 14 ground state molecular constants. The A and B reductions of the rotational Hamiltonian were found to be equivalent. Improved effective ground state and equilibrium structures were determined for both PH3 and PD3; the equilibrium structures, re (PH)=141.1607(83) pm and αe (HPH)=93.4184(95)° and re (PD)=141.1785(57) pm and αe (DPD)=93.4252(68)°, are in good agreement. 相似文献
7.
Jian TangA.R.W. McKellar L.A. Surin D.N. Fourzikov B.S. DumeshG. Winnewisser 《Journal of Molecular Spectroscopy》2002,214(1):87-93
The millimeter-wave spectrum of the normal isotope of the CO dimer, (12C16O)2, has been systematically surveyed in the regions 75-105 and 131-174 GHz, with additional measurements covering the entire 60-176 GHz range. By combining these results and using the technique of combination differences based on previously known energy levels, 14 new rotational levels have been assigned and precisely (≈0.1 MHz) located. They belong to 3 completely new states, 1 with A+ symmetry and 2 with A− symmetry. The position of the lowest energy A− state results in a new and lower value for the effective tunneling splitting of the CO dimer, 3.73 cm−1. The observation of dramatically different intensities for different bands supports the concept of two isomeric forms for (CO)2, the ground state having a larger intermolecular separation (≈4.4 Å) with most likely a C-bonded configuration, and the low-lying (0.88 cm−1) excited state having a smaller separation (≈4.0 Å) and an O-bonded geometry. 相似文献
8.
9.
Rotational transitions of DCNO in the vibrational states 00002, 00003, 00020, and 00011 have been measured and analyzed. These results complete the presentation of assigned millimeter wave transitions of DCNO.The analysis of rotational l-type resonance in the 00002 and 00020 states is more satisfactory in the case of DCNO than in that of HCNO due to the absence of accidental resonances. The values obtained for the vibrational anharmonicity constant g55 for 00002 and 00003 agree within experimental error with those found from the vibrational spectrum.An ambiguity in the assignment of the symmetry of the transitions in the four components of the 00011 vibrational state is discussed. 相似文献
10.
P. Wallraff Koichi M.T. Yamada R. Schieder G. Winnewisser 《Journal of Molecular Spectroscopy》1985,112(1):163-172
The ν4 vibration-rotation spectrum of acetonitrile (CH3CN) has been measured using a newly constructed diode-laser spectrometer controlled digitally by a microprocessor. The spectrum was observed in the range between 890 and 960 cm?1 with Doppler-limited resolution. The P and R branches of the ν4 fundamental band have been assigned up to K = 9. A small anomaly found in the high K lines is being explained by an anharmonic resonance with the v8 = 33 state. The determined interaction constant is small, but significant. 相似文献