High-resolution Fourier transform study of the ν11 and ν7 fundamentals of cyclopropane

1984 ◽  
Vol 62 (12) ◽  
pp. 1369-1373 ◽  
Author(s):  
Josef Pliva ◽  
J. W. C. Johns
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Spectroscopic Constants ◽  
Hamiltonian Matrix ◽  
Matrix Elements ◽  
Vibrational States ◽  
Coriolis Interaction ◽  
Band Origin ◽  
The Matrix ◽  
Parallel Band

The absorption spectrum of cyclopropane, C3H6, was measured in the region between 790 and 950 cm−1 on a high-resolution Fourier transform spectrometer. The section containing the Q-branches of the perpendicular band of the ν11 vibration of species E′ was deconvolved to an effective line width of 0.0020–0.0025 cm−1. The structure of the ν11 band is strongly affected by l-type resonance. A total of 88 sub-bands with KΔK = −42 to 45 have been assigned in this band. The K = 4–3 and 2–3 sub-bands both exhibit K doubling of the lines with high J resulting from a combined effect of the off-diagonal matrix elements [Formula: see text], [Formula: see text], and [Formula: see text] with the l doubling in the K = 1, l = 1 state. Otherwise, the ν11 band is found to be free of perturbations by other vibrational states, in spite of the fact that a Jx,y Coriolis interaction is allowed by selection rules with the ν7 band (species [Formula: see text]) whose band origin is only 14.38 cm−1 below that of ν11. This shows that the value of [Formula: see text] is essentially zero. Also, the allowed Jz Coriolis interaction with the ν10 state, which lies 160.01 cm−1 above ν11, does not noticeably affect the two bands. A Hamiltonian matrix, including the matrix elements responsible for the K doubling and l-type resonance, was used for the treatment of the ν11 band. A set of accurate ground state constants and spectroscopic constants for the upper state ν11 is reported that reproduces 3240 observed lines of this band with a standard deviation of 0.0009 cm−1. Lines of the parallel band ν7 are just barely seen between the ν11 lines, which are perhaps 30–50 times stronger. Spectroscopic constants for the ν7 band have been obtained from 135 individual lines assigned to the Q- and R-branches of sub-bands with K = 6–21.

The magnetic rotation spectrum of formaldehyde: singlet–triplet perturbations in the 41 and 43 levels of the Ã1A2 state of H2CO

1979 ◽  
Vol 57 (8) ◽  
pp. 1224-1232 ◽  
Author(s):  
D. A. Ramsay ◽  
S. M. Till
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Rotational Level ◽  
Magnetic Rotation ◽  
Matrix Elements ◽  
Coriolis Interaction ◽  
Near Ultraviolet ◽  
The Matrix ◽  
Rotation Spectrum

A survey of the magnetic rotation spectrum (MRS) of formaldehyde in the near ultraviolet is reported. The [Formula: see text] and [Formula: see text] bands of the [Formula: see text] system are also studied under high resolution. The rR and pP branches of these bands are found to be active and it is noted that the intensities appear to increase more rapidly with increasing Ka in the MRS than in the absorption spectrum. The 43 and 61 levels are in Coriolis interaction at higher Ka values, and some rR branches of the [Formula: see text] band are identified.Several strong lines in the MRS are shown to be associated with rR, rP, pR, and pP lines in the absorption spectrum and to reveal the presence of singlet–triplet perturbations. Only one perturbed rotational level is found in the [Formula: see text] band, but for the [Formula: see text] band several rotational levels are found to exhibit such perturbations, e.g. 190,19, 191,19, 171,16, 102,8, 102,9, 112,9, 173,14, 173,15, 183,15, and 183,16. These perturbations are produced by ΔJ = ΔN = ΔKa = 0 interactions with the 415161 level of the ã3A2 state and by ΔJ = ΔN = 0. ΔKa = ± 1 interactions with the 5161 level. The matrix elements are of the order of 0.01–0.10 cm−1.

High resolution vacuum ultraviolet absorption spectrum of N2: Perturbations in the and c4(0) 1Πu Rydberg levels

1984 ◽  
Vol 62 (12) ◽  
pp. 1478-1487 ◽  
Author(s):  
K. Yoshino ◽  
D. E. Freeman
Keyword(s):  
High Resolution ◽  
Vacuum Ultraviolet ◽  
Wavelength Region ◽  
Spectroscopic Constants ◽  
Ultraviolet Absorption Spectrum ◽  
Matrix Elements ◽  
Perturbation Matrix ◽  
Heterogeneous Interaction ◽  
Rydberg Transitions ◽  
Line Positions

High resolution absorption spectra of N2 in the wavelength region 85.73–86.65 nm have been photographed at a reciprocal dispersion of 0.03 nm/mm in the second order of a 2400 line/mm grating by a 6.65 m vacuum spectrograph. The Rydberg transitions [Formula: see text] and [Formula: see text] are analyzed. Gross irregularities in line positions and intensities are interpreted in terms of homogeneous and heterogeneous perturbations among the vibronic levels c4(0), [Formula: see text], b′(18), b(22), b(23), and b(24). A multilevel deperturbation procedure is applied to these levels to produce deperturbed spectroscopic constants. The perturbation matrix elements with the largest values are those of the homogeneous interactions [Formula: see text] and c4(0) × b(23) = 7.3 cm−1, and that of the heterogeneous interaction [Formula: see text]. Term values established for the upper levels c4(0) and [Formula: see text] of the vacuum ultraviolet (VUV) bands are combined with the recent results of Suzuki and Kakimoto for the visible bands c4(0)–a″(0) and [Formula: see text] to obtain term values of the [Formula: see text] level.

High-Resolution Fourier Transform Spectrum of the D2O Molecule in the Region of the Second Triad of Interacting Vibrational States

2000 ◽  
Vol 200 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Sheng-gui He ◽  
O.N. Ulenikov ◽  
G.A. Onopenko ◽  
E.S. Bekhtereva ◽  
Xiang-huai Wang ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Vibrational States ◽  
Fourier Transform Spectrum

High-Resolution Vibrational Spectra of Furazan IV. The Aj Fundamental v2 at ~ 1418 cm-1 from Fourier-Transform Infrared Spectroscopy

1993 ◽  
Vol 48 (5-6) ◽  
pp. 692-698
Author(s):  
Otto L. Stiefvater ◽  
Stefan Klee
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Excited State ◽  
High Resolution ◽  
Band Origin ◽  
Asymmetric Rotor ◽  
Stretching Vibration ◽  
Ft Ir ◽  
Microwave Data

Abstract The band origin of the A1 mode v2 , which represents the symmetrical stretching vibration of the two C = N bonds of furazan, has been determined from the high-resolution FT-IR band as v20 = 1418.4724± 0.0001 cm-1. The rotational parameters of this excited state, as determined in a preceding DRM microwave study, have been confirmed and their precision was raised through the combined fit of microwave data and of some 2500 rovibrational transitions.The use of conjugate low-J Q-branch lines for the determination of the origin of a B-type IR band of an asymmetric rotor is illustrated.

The infrared spectrum of aminodifluoroborane, NH2BF2: Partial assignment of the fundamentals and analysis of the band near 1608 cm−1

1988 ◽  
Vol 66 (8) ◽  
pp. 2088-2099 ◽  
Author(s):  
H. M. Jemson ◽  
W. Lewis-Bevan ◽  
M. C. L. Gerry
Keyword(s):  
Infrared Spectrum ◽  
Gas Phase ◽  
Spectroscopic Constants ◽  
Centrifugal Distortion ◽  
Coriolis Interaction ◽  
Partial Assignment ◽  
Rotational Perturbation ◽  
Band Origin ◽  
Centrifugal Distortion Constants ◽  
First Time

The infrared spectrum of gas phase aminodifluoroborane, NH2BF2, has been observed for the first time. A partial assignment to the fundamental vibrations has been made. The [Formula: see text] band has been recorded at high resolution, and the rotational and centrifugal distortion constants of NH211F2 have been obtained in both the ground and 21 levels. A small rotational perturbation in the 21 level has been attributed to a perpendicular Coriolis interaction. Using a newly written least-squares fitting program, spectroscopic constants of the unseen level have been evaluated, including its band origin and the Coriolis coupling coefficient. Possible identities of the unseen level are suggested.

Spectroscopic constants of the ground and lower vibrational states of CH281BrF: A combined high resolution infrared and microwave study

2007 ◽  
Vol 246 (1) ◽  
pp. 126-132 ◽  
Author(s):  
A. Baldacci ◽  
P. Stoppa ◽  
A. Pietropolli Charmet ◽  
S. Giorgianni ◽  
G. Cazzoli ◽  
...  
Keyword(s):  
High Resolution ◽  
Spectroscopic Constants ◽  
Vibrational States

Rotational Spectrum and 14N-Quadrupole Coupling Constants of Orthofluorobenzonitrile, a Microwave Fouriertransform Study

1986 ◽  
Vol 41 (7) ◽  
pp. 955-958 ◽  
Author(s):  
Olaf Böttcher ◽  
Dieter H. Sutter
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Vibrational State ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectrum ◽  
Frequency Range ◽  
Rotational Constants ◽  
Quadrupole Coupling

Seventyseven a-type rotational transitions of Orthofluorobenzonitrile were observed and assigned in the 8 - 25 GHz frequency range. The spectrum was recorded using the high resolution microwave Fourier transform spectrometer constructed at Kiel University. For most transitions the l4N quadrupole hfs patterns could be fully resolved. The spectroscopic constants obtained by a fit to the observed hfs-center frequencies and to the observed hfs multiplet splittings are: A = 2940.745(12) MHz, B = 1512.699(1) MHz, C = 998.633(1) MHz (rotational constants) and Χaa = - 4.114( 17) MHz, Xbb - Xcc= 0.383(34) MHz (14N quadrupole coupling constants). The rotational spectrum of a low lying vibrational state could be also assigned.

High-Resolution Vibrational Spectra of Furazan II. The B1 Fundamental ν 11 at ~ 1175 cm–1 from Fourier-Transform Infrared Spectroscopy

1992 ◽  
Vol 47 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Otto L. Stiefvater
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
High Resolution ◽  
Vibrational Spectra ◽  
Ir Spectrum ◽  
Microwave Spectroscopy ◽  
Statistical Uncertainty ◽  
Band Origin ◽  
Combined Use ◽  
Ft Ir

Abstract The high-resolution FT-IR spectrum of the A-type fundamental ν11 of furazan ( C2H2N20) has been recorded and analysed against the background of rotational information from DRM microwave spectroscopy to yield the band origin as ν110= 1175.3377 + 0.0001 cm-1 . The combined use of microwave (MW) and FT-IR data gives this band origin with a statistical uncertainty of σ= 10-6cm-1 and leads to a refinement of the rotational constants of the state ν11 = 1 over those derivable from either MW or FT-IR data alone

The Iodine Hvperfine Structure in the Microwave Spectrum of Ethyl Iodide: Nuclear Quadrupole and Spin Rotation Coupling

1988 ◽  
Vol 43 (11) ◽  
pp. 971-976 ◽  
Author(s):  
Joachim Gripp ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Microwave Spectrum ◽  
Spin Rotation ◽  
Ethyl Iodide ◽  
Hamiltonian Matrix ◽  
Matrix Elements ◽  
Coupling Matrix ◽  
Error Limit ◽  
Least Squares Fit ◽  
Nuclear Quadrupole

Abstract Some rotational transitions of ethyl iodide, CH3CH2I, have been reinvestigated by microwave Fourier transform (MWFT) spectroscopy. The iodine hyperfine structure splittings were first ana lyzed using a direct diagonalization procedure of the complete quadrupole Hamiltonian matrix. The results of this analysis showed deviations from our measurements up to 60 kHz. A new analysis using additional spin rotation coupling matrix elements reproduces our measurements within the experi­mental error limit and decreases the standard deviation of the least squares fit from 28 kHz to only 4 kHz.

Nuclear structure in a hierarchy of ideal spaces

1981 ◽  
Vol 59 (11) ◽  
pp. 1670-1673
Author(s):  
M. Banville ◽  
P.-A. Simard
Keyword(s):  
Nuclear Structure ◽  
Arbitrary Number ◽  
Ideal Space ◽  
Hamiltonian Matrix ◽  
Matrix Elements ◽  
Fractional Parentage ◽  
The Matrix ◽  
Nuclear Structure Calculations ◽  
The One ◽  
Nuclear Shell

A new method permitting nuclear structure calculations for a system with an arbitrary number of fermions in an arbitrary number of subshells is developed through a generalization of the ideal space concept used in the boson methods. The nuclear shell problem is transcribed into a hierarchy of ideal spaces; the one-to-one correspondence between the states in each ideal space permits the generation of complete bases of antisymmetric states. The Hamiltonian matrix elements for the system are given. A generalization of the fractional parentage coefficients for such systems is obtained. The symmetries of those coefficients lead to a very important reduction in the complexity of the matrix elements.

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