共查询到20条相似文献,搜索用时 31 毫秒
1.
L.H. CoudertP. Çarçabal M. ChevalierM. Broquier M. HeppM. Herman 《Journal of Molecular Spectroscopy》2002,212(2):203-207
The ν6, ν17, and ν21 fundamental bands of dimethyl ether have been assigned and rotationally analyzed. The spectra used were recorded at 0.005 cm−1 spectral resolution with a Fourier-transform spectrometer coupled to a supersonic molecular beam leading to a rotational temperature of about 70 K. The ν6 and ν21 bands do not seem to be perturbed and the analysis of the rotational structure leads to band centers located at 933.906 6(9) and 1 103.951(1) cm−1, respectively, and to accurate rotational and centrifugal distortion constants. For the ν17 band at 2817.385(2) cm−1, only the P and R branches could be assigned. 相似文献
2.
V. N. Bocharov A. P. Burtsev E. V. Dubrovskaya T. D. Kolomiitsova D. N. Shchepkin 《Optics and Spectroscopy》2010,108(4):533-543
IR spectra of the solution of SF6 molecules in liquid NF3 at 84 K have been recorded. In a solvent transmission window of 1500–1750 cm−1, two wide absorption bands with pronounced peaks in the high-frequency part are observed. The profile of these bands is explained
by the influence of the resonance dipole-dipole (RDD) interaction of the states of the simultaneous transition ν1(SF6) + ν3(NF3) and ν2(SF6) + ν3(NF3) with the states (ν1 + ν3) and (ν2 + ν3) of the SF6 molecules, respectively. The use of three isotopic modifications 32SF6, 33SF6, and 34SF6 has allowed us to vary the resonance detuning and thus to change the strength of the RDD interaction. With the liquid near
the melting point being represented as a close-packed cubic crystal, the profile was calculated and its spectral characteristics
were determined. The frequencies of the main peaks coincide with the experimental values accurate to the error. 相似文献
3.
R.Wugt LarsenF. Hegelund J. CeponkusB. Nelander 《Journal of Molecular Spectroscopy》2002,211(1):127-134
The high-resolution Fourier transform infrared spectrum of trans-glyoxal in the gas phase has been recorded in the spectral regions 700-900 cm−1, 1200-1400 cm−1, and 1600-1800 cm−1 with a resolution ranging from 0.0020 to 0.0025 cm−1. The spectrum displays extensive rotational structures which are assigned to the three fundamental bands ν6 (Au, 801.5 cm−1), ν10 (Bu, 1732.1 cm−1), and ν11 (Bu, 1312.5 cm−1). A total of ca. 5000 absorption lines have been assigned to these three bands. A simultaneous ground state combination difference analysis of all three bands yields improved ground state spectroscopic constants for trans-glyoxal. Furthermore, a number of spectroscopic constants for the ν6 and ν11 levels have been determined for the first time. 相似文献
4.
O.N Ulenikov E.S Bekhtereva V.A Kozinskaia Jing-Jing ZhengSheng-Gui He Shui-Ming HuQing-Shi Zhu C LeroyL Pluchart 《Journal of Molecular Spectroscopy》2002,215(2):295-308
The high-resolution (0.005 cm−1) Fourier transform infrared spectrum of PH3 is recorded and analyzed in the region of the fundamental stretching bands, ν1 and ν3. The ν2+ν4 and 2ν4 bands are taken into account also. Experimental transitions are assigned to the ν1, ν3, ν2+ν4, and 2ν4 bands with the maximum value of quantum number J equal to 15, 15, 13, and 15, respectively. a1-a2 splittings are observed and described up to the value of quantum number K equal to 10. The analysis of a1/a2 splittings is fulfilled with a Hamiltonian model which takes into account numerous resonance interactions among all the upper vibrational states. 相似文献
5.
F. WintherM. Schönhoff A. Huckauf E.B. Mkadmi 《Journal of Molecular Spectroscopy》2002,216(2):374-378
The hot bands in the ν1, ν2, and ν3 band systems of NC-CC-NC (3-isocyano-2-propynenitrile) have been investigated and transitions from nv9-levels with n up to 4 have been identified. Two weak bands have also been observed in the gas phase infrared spectrum at 2157 and 2410 cm−1, of which the latter is probably 2v4. A preliminary investigation of some analogous hot bands in the v4 band system of the related molecule NC-CC-CN (dicyanoacetylene) is also reported. 相似文献
6.
S.-X. Wang J. Schroderus I. Ozier N. Moazzen-AhmadiV.-M. Horneman V.V. IlyushynE.A. Alekseev A.A. KatrichS.F. Dyubko 《Journal of Molecular Spectroscopy》2002,214(1):69-79
An investigation of the torsion-rotation-vibration energies in the ν5 vibrational state in CH3CF3 has been carried out using infrared and mm-wave spectroscopy. The lowest frequency parallel fundamental band ν5 near 600 cm−1 has been measured at a resolution of 0.00125 cm−1 with Fourier transform spectroscopy for the two lowest torsional states v6=0 and 1. The cold band (v5=1, v6=0)←(v5=0, v6=0) showed no torsional splittings and looked much like a parallel band in a C3v molecule. The hot band (v5=1, v6=1)←(v5=0, v6=1) consisted of three distinct subbands, one for each torsional sublevel σ=0, +1, and −1. For the state (v5=1, v6=1), the torsional splitting was increased from ∼0.001 cm−1 to ∼0.022 cm−1 by torsion-mediated Fermi-type interaction primarily with the dark state (v5=0, v6=5). The effects of this coupling on the spectrum are striking in spite of the fact that the two interacting states are ∼100 cm−1 apart and differ by four units in v6. The large amplitude character of the state (v5=0, v6=5) is seen to be largely responsible for the unusual (k, σ) dependence of the energies in the state (v5=1, v6=1). The pure rotational spectrum in the state (v5=1, v6=0) has been measured between ∼50 and 370 GHz with Doppler-limited resolution; no σ-splitting was detected. The 3590 infrared and mm-wave frequencies measured here have been analyzed together with the 1494 measurements reported earlier by Wang et al. in an analysis of the vibrational ground state (2001, J. Mol. Spectrosc.205, 146-163). A good fit was obtained here by varying 36 parameters in a Hamiltonian which takes into account the interaction between the torsional stacks of levels for v5=0 and 1, as well as the (A1−A2) splittings measured earlier for v5=0. The explicit treatment of the interstack interactions is shown to lead to significant changes in the parameters (V0,3, V0,6) that characterize the torsional potential for v5=0. These changes have been explained quantitatively by examining the contact transformation that is implicitly applied when the interstack coupling is neglected. 相似文献
7.
The high-resolution infrared spectrum of allene has been observed in the 280-380 cm−1 region at a nominal resolution of 0.00125 cm−1 using the IR beamline at the MAX-I electron storage ring in Lund. The spectrum shows the bending fundamental of the ν11 band from which spectroscopic constants for the ν11 level have been obtained. The accompanying hot band component 2ν112-ν111 has also been assigned and analyzed. 相似文献
8.
For the first time the infrared spectrum of F2BOH in the gas phase has been observed. After optimizing the conditions for the synthesis we have been able to obtain high-resolution (2.4-3.3×10−3 cm−1) infrared spectra in the ν8, ν9, and ν4 regions with both natural and 11B monoisotopic material. Analyses of the ν8 (BF2 out-of-plane bending) and ν9 (OH torsion) fundamental bands located at 684.160 and 522.870 cm−1, respectively, for F211BOH are presented here. Existing J≤10 microwave transitions were combined with novel ground state combination differences with J≤55 formed from A-type (ν4) and C-type (ν8, ν9) bands to yield substantially improved and extended ground state parameters. Using a standard Watson-type Hamiltonian, 81 and 91 upper state parameters were obtained by fitting about 2000 lines each with σ(fit) ca. 3.5×10−4 cm−1. The 81 and 91 states both appear to be unperturbed, as indicated by the agreement of the ground and excited state centrifugal distortion constants. 相似文献
9.
The diode laser spectrum of the ν1 fundamental band of the short-lived molecule PNO has been detected with 59 R- and P-branch lines accurately measured. The lines were unambiguously assigned using the rotational and distortion constants for the ground and (100) vibrational levels found previously by microwave spectroscopy. The band origin was determined to be 860.301 228(31) cm−1 from a one parameter fit. The gas phase band origin is red-shifted by approximately 4 cm−1 from the matrix value. 相似文献
10.
The ν1 (A1, 1583.22 cm−1) and ν4 (E, 1615.33 cm−1) Si-D stretching bands of monoisotopic D3Si35Cl have been studied by FTIR spectroscopy with a resolution of 3.3×10−3 cm−1. We have assigned 2341 rovibrational lines for ν1 (Jmax=70, Kmax=19) and 6207 for ν4 (Jmax=75, Kmax=27). Both (ΔK=±1, Δ?=±1) and (ΔK=±2, Δ?=?1) interactions connect the v1=1 and v4=1 levels, the latter exerting moreover a weak ?(2, 2) interaction. These interactions were taken into account in a nonlinear least-squares fit, refining 29 free parameters with a standard deviation of 0.257×10−3 cm−1 over 6722 nonzero-weighted data. Blended lines and about 250 of the 330 lines belonging to the K=11 subband of ν1 and the KΔK=−6 subband of ν4 were zero-weighted because they are locally perturbed respectively by the neighboring upper states of the 2ν3+ν6 (E, 1561.95 cm−1) and 3ν3 (A1, 1604.81 cm−1) bands. Equivalent fits were obtained for altogether three different models obeying constraints according to the theory of unitary equivalent reductions of the rovibrational Hamiltonian. By means of a band contour simulation both the transition moment ratio |M1:M4|=0.67 and a positive sign of the Coriolis intensity perturbation were determined. 相似文献
11.
M. Carlotti G. di Lonardo G. Galloni A. Trombetti 《Journal of Molecular Spectroscopy》1976,62(2):192-200
The infrared absorption of HNCO has been measured in the region of the NH stretching fundamental and in that of the second overtone. The results for the excited states are (in cm?1):
Band | B | C | ||
3533.1 | 27.0 | — | — | |
10145.79 | 22.6713 | 0.368426 | 0.361722 |