Infrared spectrum of the fundamental ν1 of deutero-isocyanic acid

1981 ◽  
Vol 59 (10) ◽  
pp. 1313-1326 ◽  
Author(s):  
D. A. Steiner ◽  
S. R. Polo ◽  
T. K. McCubbin Jr. ◽  
K. A. Wishah

The ν1 fundamental band of DNCO has been observed for the first time under high resolution. The band origin for this deuterium–nitrogen stretching vibration is found to be at 2637.198 cm−1, rather distant from the previously reported value of 2634.9 cm−1. Eighteen subbands have been analyzed and term values for both ground and ν1 states with K up to 6 have been obtained. Effective rotational constants Bν and centrifugal distortion constants Dν and Hν have also been determined. Interaction is observed with the 2ν3 vibration which has a band origin around 2640 cm−1. Interesting perturbations are observed for the K = 0 and K = 4 levels of ν1.


1988 ◽  
Vol 66 (8) ◽  
pp. 2088-2099 ◽  
Author(s):  
H. M. Jemson ◽  
W. Lewis-Bevan ◽  
M. C. L. Gerry

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.



1991 ◽  
Vol 46 (8) ◽  
pp. 710-714 ◽  
Author(s):  
Volker Meyer ◽  
Dieter Hermann Sutter ◽  
Helmut Dreizler

AbstractThe pure rotational spectrum of sulfur trioxide has been observed for the first time. A total of 25 high-J transitions could be assigned. The rotational constants, two quartic centrifugal distortion constants, and three sextic centrifugal distortion constants were determined as: B= 10 449.0667(23) MHz, C = 5216.0330(12) MHz, DJ = 9.2651 (18) kHz, DJK = -16.3922(18) kHz, HJ, = -8.8(34) • 10-3 Hz, HJK= -15.8(73) • 10-3 Hz, and HKJ = 34.2(73) • 10-3 Hz. An r0- and an re -structure are presented: r0= 1.4198(7) Å (calculated from B), r0 = 1.4210(7) Å (calculated from C), and re = 1.4175 Å



1988 ◽  
Vol 43 (4) ◽  
pp. 331-337 ◽  
Author(s):  
A. Gambi ◽  
A. Baldacci ◽  
S. Giorgianni

Abstract The infrared spectrum of diazirine has been recorded at Doppler resolution with a high informa­tion Fourier transform spectrometer. The ν3 fundamental has been reinvestigated and the overall assignment of the rovibrational transitions has been carried out. From the least-squares analysis a more accurate set of molecular constants including the sextic centrifugal distortion constants has been determined for the level υ3 = 1 and will be reported here. The higher resolution achieved here allowed the assignment of weaker lines and many Q branch transitions. Moreover many blended lines have now been resolved and could be properly assigned.



2014 ◽  
Vol 92 (9) ◽  
pp. 855-861 ◽  
Author(s):  
Salman Mahmoud ◽  
Mahmoud Korek

The potential energy curves of the low-lying electronic states of the LaH molecule are reported via the CASSCF method with multireference calculations (single and double excitations with Davidson corrections). Twenty-four low-lying electronic states of the LaH molecule in the representation 2s+1Λ(+/−) below 20 000 cm−1 were investigated along with five lower electronic states in the Ω representation. The harmonic frequency ωe, the equilibrium internuclear distance Re, the rotational constants Be, and the electronic energy with respect to the ground state Te were calculated for these states. Twelve new electronic states are investigated in the present work for the first time that have not yet been observed experimentally. Using the canonical functions approach, the eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constants Dv, and the abscissas of the turning points Rmin and Rmax were calculated for the investigated electronic states up to vibrational level v = 43.



1974 ◽  
Vol 29 (5) ◽  
pp. 698-701 ◽  
Author(s):  
Mikko Huhanantti

Abstract The rotational structures of the ν1 bands of the deuterated monohaloacetylenes DCCF and DCCBr were investigated. The rotational constants B in the ground state and in the vibrational states involved were obtained. The centrifugal distortion constants D were calculated from the force constants and the geometrical data, too. The results D = 8.7 x 10-8 cm-1 for DCCF and D = 1.9 x 10-8 cm-1 for DCCBr are compatible with the experimental values (12 ± 4) x 10-8 cm-1 and(2±2) x 10-8 cm-1, respectively.



2001 ◽  
Vol 79 (2-3) ◽  
pp. 461-466
Author(s):  
C Xia ◽  
A RW McKellar

The infrared spectrum of the weakly-bound molecular complex methanol - carbon monoxide has been observed, for the first time in the gas phase, by means of a parallel (Δ K = 0) band in the region of the carbon monoxide C–O stretching vibration. The band origin, 2154.5 cm–1, represents a blue shift of 11.2 cm–1 relative to the free CO molecule; its proximity to that of the H2O – CO complex points to a similarity of the hydrogen bonding in the two systems. The observed structure of the band could be well reproduced by a simulation based on the methyl internal rotation component of A-symmetry. A component of E-symmetry must also be present, with roughly equal intensity, but the two components were not individually resolved. The observed transitions showed evidence of predissociation broadening, leading to an estimate of t [Formula: see text] 0.5 ns for the lifetime of the upper (C–O stretching) state.PACS Nos.: 3320E, 3425, 3520P, 3640



1984 ◽  
Vol 62 (12) ◽  
pp. 1452-1466 ◽  
Author(s):  
L. Fusina ◽  
M. Carlotti ◽  
B. Carli

The infrared spectrum of isocyanic acid, HNCO, has been recorded in the range 8–80 cm−1 with a resolution of about 0.004 cm−1a-type and b-type rotational transitions have been measured and assigned in the ground state and in the ν4 = 1, ν5 = 1, ν6 = 1, and ν5 = 2 vibrational states.Improved values of the ground state rotational and centrifugal distortion constants in the Ir S-reduced Hamiltonian of Watson have been obtained in a simultaneous analysis of our measurements and microwave, millimetre-wave, and far infrared data reported previously. Sub-band origins and effective spectroscopic constants have been determined for each excited vibrational state. An accurate value for the ν6 band origin, at 656.287 cm−1, has been deduced.



2001 ◽  
Vol 79 (2-3) ◽  
pp. 479-482 ◽  
Author(s):  
D B Braund ◽  
A RH Cole

The spectrum of trans-glyoxal has been recorded at a resolution of about 0.004 cm–1 in the region from 2770 to 2900 cm–1. 1549 lines have been assigned to the type B band due to the υ9 (bu) fundamental (antisymmetric C–H stretching vibration). The ground-state rotational constants confirm earlier values and new constants are determined for the excited state of υ9. PACS No.: 33.20E



1981 ◽  
Vol 36 (10) ◽  
pp. 1052-1056 ◽  
Author(s):  
Koichi Yamada ◽  
Gisbert Winnewisser

The CN stretching band, ν2, of cyanobutadiyne has been detected by a tunable diode laser spectrometer in the wavenumber range from 2250 to 2260 cm-1. The P-and R-branch transitions, up to P(77) and R(75), of the fundamental band were identified and measured with the accuracy of 0.001 cm-1. The band origin was obtained to be 2256.12406(13) cm-1. The rotational and centrifugal distortion constants in the excited vibrational state, B′ and D′, were also determined.



1994 ◽  
Vol 72 (11-12) ◽  
pp. 1165-1178 ◽  
Author(s):  
Sybille Haas ◽  
Gisbert Winnewisser ◽  
Koichi M.T. Yamada

The ν7 infrared band of cyanobutadiyne (HC5N) was recorded for the first time with high resolution by FTIR spectroscopy using a sample produced by gas electric discharge. The fundamental band and the hot bands arising from the ν11 = and 2 states are identified. The molecular parameters, including the rotational and vibrational ℓ-type doubling constants, have been determined accurately by analyzing the spectra together with the available microwave and millimetre wave data. The intensity perturbation caused by the ℓ-type resonance in the (ν7,ν11) = (1,1) state has been clearly observed and discussed.



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