Microwave spectrum of allyl cyanide (CH2=CHCH2CN)

1968 ◽  
Vol 46 (8) ◽  
pp. 959-962 ◽  
Author(s):  
K. V. L. N. Sastry ◽  
V. M. Rao ◽  
S. C. Dass

The microwave spectrum of allyl cyanide (3-butenonitrile) was studied in the region from 8 to 26 GHz. It was confirmed that this molecule exists in the two rotational isomers "cis" and "gauche". In the cis form, both a- and b-type transitions were assigned and the rotational constants in the ground vibrational state were calculated to be A = 11 323.01 + 0.08 MHz, B = 3739.20 ± 0.01 MHz, C = 2858.52 ± 0.01 MHz. The molecular dipole-moment components are μa = 3.26 ± 0.01 D, μb = 2.16 ± 0.05 D, and μt = 3.91 ± 0.03 D. For the gauche form, the a-type transitions were assigned and the rotational constants in the ground vibrational state are A = 17 295 MHz, B = 2619.91 ± 0.1 MHz, C = 2497.52 ± 0.1 MHz. The Stark effect measurement in this case gave the components of the dipole moment as μa = 3.69 ± 0.02 D, ub = 1.11 ± 0.06 D, μc = 0.98 ± 0.07 D, and μt = 3.98 ± 0.03 D.

1969 ◽  
Vol 47 (8) ◽  
pp. 1289-1293 ◽  
Author(s):  
V. M. Rao ◽  
R. Kewley

The microwave spectrum of tetrahydropyran has been recorded in the region 8–40 GHz. The rotational constants of the molecule in its ground vibrational state are, in MHz, A = 4673.48 ± 0.05, B = 4495.02 ± 0.11, and C = 2601.31 ± 0.05. The dipole moment components are, in Debye units, μa = 1.53 ± 0.02, μc = 0.82 ± 0.02, and μ = 1.74 ± 0.03. The direction of μ with respect to the principal axes of rotation together with the rotational constants show that the observed spectrum is due to the chair form of tetrahydropyran.


1972 ◽  
Vol 50 (11) ◽  
pp. 1690-1697 ◽  
Author(s):  
R. Kewley

The microwave spectrum of 1,3-dioxane has been studied within the region 8 to 40 GHz. The rotational constants of the molecule in its ground vibrational state are, in MHz, A = 4999.94(0.05), B = 4807.61 (0.05), and C = 2757.12(0.05). The dipole moment components are, in Debye units, μb = 1.61 (0.02), μc = 1.29(0.01), and μ = 2.06(0.03). The values of the above quantities are consistent with a chair form structure. Rotational spectra due to five excited vibrational states of 1,3-dioxane have been assigned.


1974 ◽  
Vol 29 (10) ◽  
pp. 1498-1500 ◽  
Author(s):  
W. Czieslik ◽  
L. Carpentier ◽  
D. H. Sutter

Abstract The microwave spectrum of Methylenecyclobutenone has been investigated in the vibrational ground state in the range of 8 to 26.5 GHz. From a least square fit of 12 lines with J ≦ 4 the rotational constants have been calculated as A =5.775664±0.000009 GHz, B = 4.312314 ± 0.000007 GHz, C = 2.467814±0.000008 GHz. The inertia defect Δ = - 0.09 amuÅ2 indicates that the molecule is planar. From Stark-effect measurements the components of the molecular electric dipole moment were obtaied as |μa| = 2.04 ± 0.02 D, |μb| = 2.70±0.03 D, |μtotal| = 3.39 ± 0.05 D.


1971 ◽  
Vol 26 (11) ◽  
pp. 1809-1812 ◽  
Author(s):  
E. Tiemann

Stark-effect measurements on pure rotational transitions of TlBr and Til are described. The derived electric dipole moments of the most abundant isotopic molecules on the ground vibrational state are:205TL79Br : | μ0| = (4.493 ± 0.050) D , 205Tl127 I | μ 0| =(4.607 ± 0.070) D .The electric dipole moment of 205Tl19F | μ 0|=4.2282 (8) D was used as standard.


1991 ◽  
Vol 46 (3) ◽  
pp. 229-232 ◽  
Author(s):  
J.-U. Grabow ◽  
N. Heineking ◽  
W. Stahl

AbstractWe recorded the microwave spectrum of hexafluoropropanone between 7 and 15 GHz using a pulsed molecular beam microwave Fourier transform spectrometer. The rotational constants were determined to be A = 2181.71980(14) MHz, B= 1037.22930(7) MHz, C = 934.89233(8) MHz, the quartic centrifugal distortion constants are D'J= 0.07378 (39) kHz, D'JK = 0.10002(75) kHz, D'K = -0.07269(266) kHz, δ'J = 0.00623(29) kHz and R' 6= 0.00755(12) kHz. Stark effect measurements yielded a dipole moment μ = μb= 0.3949 (18) D


1969 ◽  
Vol 24 (8) ◽  
pp. 1217-1221 ◽  
Author(s):  
J Hoeft ◽  
F.J. Lovas ◽  
E Tiemann ◽  
R Tischer ◽  
T Törring

Stark-effect measurements on pure rotational transitions of GeO and GeS are described. Measurements on the ground vibrational state of the most abundant isotopic molecules resulted in the following electric dipole moments: 74Ge18O μ = (3,28±0,10) D; 74Ge32S μ = (2,00 + 0,06) D . Due to improved resolution and sensitivity of the spectrometer, the rotational spectra of GeS were measured in more detail and with greater accuracy than previously. The derived rotational constants, Y01 , Y11, Y21 and Y02 , are reported.


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.


1973 ◽  
Vol 51 (4) ◽  
pp. 529-532 ◽  
Author(s):  
R. Kewley

The microwave spectrum of cyclohexene sulfide (7-thiabicycIo[4,1,0]heptane) has been investigated in the 26.5–40 GHz region. R-branch lines due to both a- and c-type transitions have been assigned for the ground vibrational state and for the first excited states of the ring bending and ring twisting modes. From relative intensity measurements the frequencies of these two modes are estimated as: vbend = 115 ± 20 cm−1 and vtwist = 200 ± 60 cm−1. The rotational constants for the ground vibrational state are (in MHz): A = 3512.086 ± 0.010, B = 2057.969 ± 0.003, and C = 1623.023 ± 0.003. These values are consistent with a twisted half chair structure for the heavy atom skeleton of cyclohexene sulfide, similar to that of cyclohexene oxide.


1977 ◽  
Vol 55 (19) ◽  
pp. 3480-3486 ◽  
Author(s):  
R. Kewley ◽  
S. C. Dass

The microwave spectra of two conformers of 1-methoxy-1,3-butadiene have been studied in the 18 to 40 GHz region. One conformer is the s-trans conformer of trans-1-methoxy-1,3-butadiene. The other is most likely the corresponding s-cis conformer. The rotational constants for the ground vibrational state are (in MHz) s-trans: A = 24 524(16); B = 1336.51(1); C = 1277.76(1); s-cis: A = 12 642.73(23); B = 1607.61(1); and C = 1439.64(1). The centrifugal distortion parameters DJK and DJ have also been determined for each conformer.For the s-trans conformer two series of torsional satellites have been found which are assigned as O—CH torsion with frequency 60(20) cm−1 and =C—C= torsion, frequency 80(30) cm−1. For the s-cis conformer one series of satellites has been observed, which has been assigned to =C—C= torsion, of frequency 103(30) cm−1.


1969 ◽  
Vol 47 (18) ◽  
pp. 3453-3462 ◽  
Author(s):  
J. J. Sloan ◽  
R. Kewley

The microwave spectra of morpholine and N-deuteromorpholine have been investigated within the 8 to 40 GHz region. For both the normal and the deuterated species, strong a-type spectra which are due to the chair conformer with an equatorial imino group were recorded. The ground vibrational state rotational constants and quadrupole coupling constants are (in MHz), for normal morpholine, A = 4924.88 ± 0.05, B = 4625.15 ± 0.05, C = 2684.25 ± 0.05, χaa = 2.22 ± 0.02, χbb = 2.51 ± 0.04, χcc = −4.73 ± 0.02, and for N-deuteromorpholine, A = 4925.39 ± 0.05, B = 4399.67 ± 0.05, C = 2607.09 ± 0.05, χaa = 1.92 ± 0.02, χbb = 2.59 ± 0.04, χcc = −4.51 ± 0.02. The rs coordinates of the imino hydrogen are (in Å) aH = 2.373 ± 0.005 and cH = 0.10 ± 0.03. For the normal species the dipole moment components are (in D) μa = 1.68 ± 0.01, μc = 0.30 ± 0.01, μ = 1.71 ± 0.02. The value of aH and the direction of μ with respect to the a and c principal axes confirm that the observed spectrum is that of the chair equatorial conformer of morpholine.


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