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1.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1989,45(2):153-157
A type (ΔKa = 0) rovibrational lines of the near-prolate asymmetric top 16O14N35Cl have been assigned on high resolution Fourier transform spectra: 820 lines of the ν1 band, centered around 1800 cm−1, 435 lines of the ν1 + ν3 band, centered around 2131 cm−1, and 257 lines of the ν2 + ν3 band, centered around 925 cm−1. Least-squares calculations have been carried out over these lines, using the A reduced Watson's hamiltonian in Ir representation; r.m.s. standard deviations of 0.0016 cm−1, 0.0016 cm−1 and 0.006 cm−1 have been respectively obtained, making it possible to measure molecular constants of the (001), (101) and (011) vibrational levels of 16O14N35Cl. 相似文献
2.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1988,44(8):783-784
Two hundred and sixty A type rovibrational lines of the ν2 + ν3 vibrational band of 16O14N35Cl, around 925 cm−1, have been assigned; a least-squares calculation with a r.m.s. deviation of 0.0006 cm−1 has made it possible to measure several constants of the (011) vibrational level. 相似文献
3.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1982,38(8):899-902
The effect of temperature upon the ν(OH) bands of nine hydroxy apatites has been studied and discussed in relation to earlier results. 相似文献
4.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1977,33(6-7):689-698
Infrared spectrum of methyl cyanide was recorded in the region from 2235–2320 cm−1 with a working resolution of 0.05 cm−1. The transitions of two parallel type bands ν2 and ν3 + ν4 as well as the associated hot bands are assigned. Since the molecular constants for the ground and ν8 vibrational states are known precisely by microwave study for this molecule, highly accurate molecular constants for the upper vibrational states have been determined from those data by a least-squares procedure. 相似文献
5.
Wübbeler G Padilla Víquez GJ Jousten K Werhahn O Elster C 《The Journal of chemical physics》2011,135(20):204304
Recently, results for the CO(2) R(12) line strength parameter have been reported, which differ significantly and are inconsistent with respect to quoted uncertainties. We investigate to what extent this inconsistency might be caused by the chosen data analysis methods. To this end, we assess and compare a parametric fitting procedure and a non-parametric approach. We apply the methods to simulated and measured line spectra, and we specify the conditions required for the safe application of the two procedures. For our present data, the corresponding conditions are satisfied for both methods, and consistent results are obtained. However, the simulations reveal that the fitting procedure can show shortcomings when the uncertainty in the wavenumber is large. 相似文献
6.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1983,39(6):551-553
Vibration-rotation i.r. spectrum of ν2 of methyl iodide was measured with a resolution of 0.08 cm−1. The spectrum was analyzed by taking account of an xy-type Coriolis interaction between ν2 and ν5 and a Fermi resonance between ν5 and ν3 + ν6. The analysis gave values of spectroscopic parameters which include (ν0)2 1251.193 cm−1, A2-A0 0.02030 cm−1, (DJ)2 2.08 × 10−7 cm−1, (DJK)2 3.2 × 10−6 cm−1 and ζ2,5ay −0.6305. 相似文献
7.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1981,37(8):615-626
The rovibrational spectra of CF379Br and CF381Br in the region of ν2+ν3 near 1120 cm−1 and ν1+ν2+ν3 near 2200 cm−1 have been investigated with a resolution of 0.04 and 0.03 cm−1 respectively. The rotational J structures have been resolved and were analyzed by means of polynomial and band contour simulation procedures. Molecular parameters (ν0, xij, αA,B) have been obtained from the analysis of the cold bands and the hot bands involving ν6, 2ν6, ν3 and ν5 for both isotopomers. 相似文献
8.
Bane MK Thompson CD Robertson EG Appadoo DR McNaughton D 《Physical chemistry chemical physics : PCCP》2011,13(15):6793-6798
High resolution FTIR spectra have been recorded in the region 250-770 cm(-1) using synchrotron radiation and over 2000 transitions to the ν(8) and ν(12) states of the short lived species ketenimine have been assigned. Ground state combination differences combined with published microwave transitions were used to refine the constants for the ground vibrational state. Rotational and centrifugal distortion parameters for the v(8) = 1 and v(12) = 1 levels were determined by co-fitting transitions, and treating a strong a-axis Coriolis interaction. Selection rules for the observed ν(12) transitions indicate that they arise solely from "perturbation allowed" intensity resulting from this Coriolis interaction. 相似文献
9.
Bane MK Robertson EG Thompson CD Appadoo DR McNaughton D 《The Journal of chemical physics》2011,135(22):224306
High-resolution FTIR spectra of the short lived species ketenimine have been recorded in the region 700-1300 cm(-1) and over 1500 transitions of the ν(10) and ν(6) modes have been assigned. Effective rotational and centrifugal distortion parameters for the v(10) = 1 and v(6) = 1 (excluding K(a) = 5) states were determined by co-fitting transitions, and treating strong a- and c-axis Coriolis interactions between them. Other perturbations attributed to interactions with the v(8) = 2 and v(12) = 1 + v(8) = 1 dark-states were also observed and treated. The ν(10) transitions are predicted to be inherently very weak, but are enhanced by an intensity stealing effect with the highly IR active ν(6) mode. A mechanism for this intensity stealing in ketenimine is also detailed. 相似文献
10.
《International journal of mass spectrometry and ion processes》1998,172(1-2):129-135
The radiative relaxation of CO+(X2∑+, ν) ions produced by ionization of CO and of OCS with 70 eV electrons has been investigated using the monitor ion technique in a triple FT ICR spectrometer. Since the monitor reaction is exothermic for ν ≥ 1, the experimental lifetimes, 170 ms for CO+ from CO and 210 ms for CO+ from OCS, should correspond to the overall decay rate of ν ≥ 2 with a small contribution of ν = 1.These values being much larger than the theoretical lifetime of ν = 1 (128.5 ms), computer-simulated overall lifetimes for ν ≥ 1 and ν ≥ 2 have been determined using theoretical lifetimes calculated by Rosmus and Werner and a vibrational population deduced from photoelectron spectroscopy of CO with 40.8 eV photons (Gardner and Samson). The computer-simulated lifetimes, 250 ms for ν ≥ 1 and 125 ms for ν ≥ 2, are indeed about twice as large as the theoretical lifetimes for ν = 1 and ν = 2, respectively, indicating that the large experimental lifetimes may be accounted for by radiative cascade from the upper vibrational levels. 相似文献
11.
The ν2 and ν5 bands of CH335Cl and CH337Cl between 1300 and 1600 cm−1 have been analysed using a Fourier transform spectrum with 0.006 cm−1 resolution. For CH335Cl, the microwave data and 1200 lines from the IR spectrum with J⩽ 50 were fitted with an overall r.m.s. error of 0.00079 cm−1 using the method of predicative observations. A similar fit for 900 lines of CH337Cl gave an overall r.m.s. error of 0.00055 cm−1, providing erroneous microwave data on the ν5 level are omitted. Improved molecular constants are reported for both isotopic species. As expected, the values for ν2 and ν5 are little affected by chlorine isotopic substitution. 相似文献
12.
About 6400 lines belonging to the ν2 + ν±14, ν2 + 3ν±16, ν1 + ν±15, ν±14 + ν±15, ν±14 + ν±5, ν±5 + 3ν±16 and ν±5 + 3ν±36 bands have been assigned. An r.m.s. deviation of 0.047 cm−1 has been achieved by a least-squares fit of 1427 lines. For this purpose, a simplified model, taking into account five anharmonic resonances already found in a previous work [Molec. Phys. 70, 849 (1990)] and the well known x-y Coriolis resonance between the ν2 and ν5 modes of methyl halides, was used. Although not observed, the ν±14 + ν±15 and ν1+ ν2 parallel bands are strongly coupled by Coriolis resonance to ν2 + ν±14 and ν±15 respectively. A few secondary resonances remain unexplained in several parts of the spectrum. 相似文献
13.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1990,46(5):741-745
The inactive F2u vibration frequency of octahedral XY6 type species for which this frequency is known, was estimated from the remaining frequencies using the Urey—Bradley (UBFF) and orbital valency (OVFF) force fields and their modifications. Various modifications of the generalized valency force field (GVFF) were also considered. Estimated values were scattered within a wide range and the average discrepancy varied from 20 (UBFF) to 68% (modified OVFF). The condition ν6 = ν5/√2 (Wilson's rule), with an average discrepancy of 15% gave the closest estimate of the assigned values. 相似文献
14.
15.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1984,40(10):929-938
The gas phase i.r. spectrum of CF3I has been investigated in the ν2, ν3, 2ν3 and ν2 + ν3 region with a resolution of 0.04 cm−1. Rotational J clusters have been resolved, and several vibrational and rovibrational parameters of ν2, 743.364(8) cm−1 and ν3, 286.303(3) cm−1, have been determined by polynomial methods and by band contour simulation. 相似文献
16.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1992,48(9):1273-1281
We report N2-broadening coefficients for rovibrational transitions of the ν3 band of ozone in the temperature range 180–296 K. We assume a power law dependence of the temperature for these coefficients, with a temperature exponent n. For the 21 transitions we measured, the average value of n is 0.74 and is well within experimental error of the theoretically predicted value of 0.77. The significance of this parameter in modeling atmospheric IR absorbance due to ozone is discussed. 相似文献
17.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1994,50(8-9):1397-1412
High resolution IR spectra of the overtones and the combination band of the ν4 and ν6 modes of formaldehyde (2ν4, ν4 + ν6 and 2ν6) were measured in the region of 2200–2650 cm−1 using FTIR. The combination band ν4 + ν6, whose dipole transition is forbidden from molecular symmetry, was observed due to the intensity borrowed from the other bands. The observed frequencies were analysed by a Hamiltonian in which A-type Coriolis interactions and Darling—Dennison interaction were taken into account. The ratio and the relative signs of the transition dipole moments of the overtone bands, μ2ν4 and μ2ν6, have been determined by analysing the intensity distribution of the vibration—rotation lines. 相似文献
18.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1989,45(2):175-179
The ν3 + ν6 band of CH3 79Br has been directly analyzed for the first time, and an r.m.s. standard deviation of 0.0035 cm−1 was obtained over 394 lines of K″ΔK = 2 up to 12, through a least-squares calculation using an unperturbed model. Nevertheless discrepancies occur on sub-bands with K″ ⩾ 9, which remain not yet understood. In particular it seems difficult to explain them by a Fermi resonance with the ν5 band, since it has been possible to fit properly around 580 lines of this band, belonging to sub-bands K″ΔK = 7 up to 16, taking only into account the Coriolis resonance with the ν2 band and the l(2,2) resonance of ν5. 相似文献
19.
High rotational levels of the 001 (Σ(u)) state of BeD(2) are perturbed by the nearby 03(3)0 (Φ(u)) state. Deperturbation analysis results in an experimental value for the vibrational energy of the 030 level. 相似文献
20.
The applicability of a previously developed model on five saturated alcohols, for the calculation of the νOH gas frequency has been tested for the rotamers in equatorial and axial cyclohexanol and 1-methyl-cyclohexanol. Not only the νOH differences between the various rotamers are reasonably well predicted, but also the absolute values of the frequencies. Further analysis of the results suggests that the model is suitable at least to calculate the νOH frequency difference between the corresponding rotamers of secondary and tertiary cyclohexyl alcohols. 相似文献