Sub-millimeter Wave Spectra of Cyanoacetylene and Revised Ground State Constants

1995 ◽  
Vol 50 (12) ◽  
pp. 1179-1181 ◽  
Author(s):  
K. M. T. Yamada ◽  
A. Moravec ◽  
G. Winnewisser

Abstract Sixteen new rotational transitions of cyanoacetylene in the ground vibrational state have been measured in the frequency region from 570 GHz to 710 GHz by the Cologne sub-millimeter wave spectrometer. The observed transition frequencies were analyzed together with unpublished millimeter wave data of our group and with the data available in the literature. Precise rota­ tional constant and the quartic and sextic centrifugal distortion constants have been determined; B = 4549.058224(37) MHz, D = 0.544110(19) kHz, and H = 0.0345(21) mHz.

1975 ◽  
Vol 30 (5) ◽  
pp. 672-689 ◽  
Author(s):  
Koichi Yamada ◽  
Manfred Winnewisser

Abstract The pure rotational spectrum of vinyl isocyanide in the ground vibrational state has been as-signed in the frequency region from 8 GHz to 180 GHz. The measured absorption lines encompass 157 a-type transitions from the qRK , qQ1, qQ2,qQ3, qQ4 and qQ5 branches and 48 b-type transitions from the rP0 , rP1, rP2, rP3 , rP4 , rP5, rQ0 , and rQ1 branches for values of J up to 54. The rotational constants have been refined and all quartic and sextic centrifugal distortion constants have been determined using Watson's reduced Hamiltonian. No quadrupole hyperfine splitting was observed.


1975 ◽  
Vol 30 (8) ◽  
pp. 1001-1014 ◽  
Author(s):  
Manfred Winnewisser ◽  
Gisbert Winnewisser ◽  
T. Honda ◽  
E. Hirota

Abstract The pure rotational spectrum of trans-acrolein in the ground vibrational state has been assigned in the frequency region from 8 GHz to 180 GHz. The measured absorption lines encompass a-type transitions from the qRK, qQ1, qQ2 branches and 6-type transitions from the rP0, rP1, rP2, rR0 brandies for values of J up to 23. The rotational constants have been refined and all quartic and sextic centrifugal distortion constants have been determined using Watson's reduced Hamiltonian. This information has been used to predict line positions of astrophysical interest to warrant the interstellar line search for trans-acrolein.


2003 ◽  
Vol 58 (5-6) ◽  
pp. 275-279 ◽  
Author(s):  
A. Guarnieri ◽  
A. Huckaufa

The pure rotational spectra of [18O]ketene, H2C=C18O, [1-13C]ketene, H2C=13CO, and [2-13C]ketene, H213C=CO, have been revisited in the frequency region 200 - 350 GHz in the ground vibrational state.From more than 100 R-branch transitions for each isotopomer a set of rotational and centrifugal distortion constants could be derived using the Watson S-reduction formalism. The values obtained for the rotational constants B and C agree very well with results of former investigations. The agreement is worse with respect to the A constants, but our newly determined A values agree well with the corresponding values of the main species and the 17O isotopomer.


1977 ◽  
Vol 32 (10) ◽  
pp. 1108-1118 ◽  
Author(s):  
William H. Hocking ◽  
Gisbert Winnewisser

The microwave and millimeter wave spectra of two isotopically substituted species of monothioformic acid, H13COSH and HC18OSH. have been investigated. Over 60 rotational transitions in the ground vibrational state have been assigned and measured for both the eis and trans thiol rotamers. HC(:O)SH. of each isotopic species. Rotational constants and quartic centrifugal distortion comstants of H13COSH and HC18OSH have been determined from the observed spectra. These data have been combined with previously published results on HCOSH, DCOSH. HCOSD and HCO34SH to obtain complete substitutions structures for the planar eis and trans rotamers of HC(:O)SH. All of the in-plane bond angles as well as the SH distance are significantly different for the two rotamers. For the eis rotamer the HSC and HCS angles increase by more than 2°, the OCS angle decreases by more than 3°, and the SH bond shortens compared to the trans rotamer geometry. The eis structure is: r(C-H) = 1.104 ± 0.003 Å, r(C = O) 1.203 ± 0.003 Å. r(C-S) = 1.771 ± 0.003 Å, r(S-H) = 1.335 ± 0.002 Å, ∢(OCS) = 122.5° ± 0.3°, ∢(HSC) = 94.9° ± 0.2° and ∢(HCS) = 114.4° ± 0.2°; whereas the trans structure is: r(C-S) = 1.104 ± 0.003 Å. r(C = O) = 1.205 ± 0.003 Å, r(C-S) = 1.768 ± 0.003 Å, r(S-H) = 1.354 ± 0.002 Å. ∢(OCS) = 125.9° ± 0.3°, (HSC) = 92.5° ± 0.2° and ∢(HCS) = 111.0° ± 0.2°


2005 ◽  
Vol 60 (8-9) ◽  
pp. 619-628 ◽  
Author(s):  
Antonio Guarnieri

The pure rotational spectra in the ground vibrational state of (1,2-13C)ketene, H213C=13CO, (D2,1-13C)ketene, D2C=13CO, (D2,2-13C)ketene, D213C=CO, and (D2,18O)ketene, D2C=C18O, have been observed in the frequency region 200 - 350 GHz. All the spectral lines have been measured in natural abundances with a source modulated millimeterwave spectrometer.From the measured R-branch transitions a set of rotational and centrifugal distortion constants for each isotopomer could be derived, using the Watson S-reduction formalism. Further, the rotational spectra of the two isotopomers (4,5-D)ketene, D2CCO, and (4-D)ketene, DHCCO, which were already measured several years ago, have been extended to higher J-values and higher frequencies, as it is the case for all investigated isotopomers of this work. As a result of these studies a calculation of a mass-dependent structure will be the topic of a next paper.


1987 ◽  
Vol 42 (11) ◽  
pp. 1275-1278
Author(s):  
H. Zerbe ◽  
A. Guarnieri

The microwave and millimeterwave spectrum of 15N-fluoracetonitrile(CH2FC15N) in the ground vibrational state are investigated in the region between 8 and 150 GHz. The measured transitions are fitted to a Hamiltonian with three rotational constants, five quartic and seven sextic centrifugal distortion constants in the symmetric top limit of van Eijck-Typke and in the s-reduction of Watson. The rotational constants are used to improve the calculated r0 -restructure of the fluoracetonitrile molecule.


1969 ◽  
Vol 24 (12) ◽  
pp. 1973-1979
Author(s):  
Hans Karl Bodenseh ◽  
Manfred Winnewisser

The microwave spectrum of the deuterated form of fulminic acid (DCNO) has been investigated in the frequency region from 9 to 42 GHz. For the ground vibrational state of DCNO the following rotational constants were obtained: B0(D12C14N16O) =10 292.50 MHz,B0(D13C14N18O) =10 011.66 MHz,B0(D12C14N18O) = 9 758.87 MHz. The corresponding moments of inertia yield a combined rs and r0 structure: rDC = 1.027 ±0.001 Å, rCN = 1·168 ±0.001 Å, rNO = 1.199 ± 0.001 Å. For the two degenerate bending modes ν4 and ν5 the l-type doublets of the transition J = 1 - 2 and the two corresponding series of l-type doubling transitions have been observed. The analysis of the two l-type doubling series revealed that P4 and P6 centrifugal distortion contributions are sufficient to account for the spectrum. The doubling constants given in MHz are q4 = 17.9103-(0.6467 · 10-4)J(J + 1) +(0.188 · 10-8) [J(J + 1)]2, q5 = 38.0907-(0.3061 · 10-3)J(J + 1) + (0.314 · 10-8)[J(J + 1) ]2. A third series of l-type doubling transitions arising from the II-level of the ν5=3 vibrational state has been found and analysed, yielding: q(0)3×5 =29.2748 ± 1.8 · 10-4 MHz; EΦ-EII=Δ ≅ 41 cm-1.


1989 ◽  
Vol 44 (6) ◽  
pp. 538-550 ◽  
Author(s):  
J. Doose ◽  
A. Guarnieri ◽  
W. Neustock ◽  
R. Schwarz ◽  
F. Winther ◽  
...  

D2CCO has been investigated in the first excited vibrational states of the ν9, ν6, and ν5 vibrations. About 150 transitions have been measured partly at room temperature and partly at 360 K using a micro- and millimeter-wave spectrometer provided with an averaging system using a personal computer. Rotational and centrifugal distortion constants have been obtained for the excited states mentioned. A simultaneous least squares analysis of these MW-data with upper state combination differences obtained from FT-IR data has been carried out. Improved sets of molecular parameters have been obtained.


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