scholarly journals Microwave Spectra of Dimethylether (CH3)2O and (CD3)2O in Excited Torsional States

1978 ◽  
Vol 33 (12) ◽  
pp. 1498-1510 ◽  
Author(s):  
H. Lutz ◽  
H. Dreizler

Abstract The rotational spectra of the torsional excited states v̅n = 11,12,21, 22, 23 have been measured and assigned. The torsional fine structure was used to determine the coefficients V3 and V' 12 of the hindering potential. For (CH3)2O : V3 = 2618 ± 4 cal/mole, V'12 = 18 ± 8 cal/mole, for (CD3)2O : V3 = 2572 ± 6 cal/mole, V'12 = 29 ± 12 cal/mole, V12 was correlated to V3 .

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1117-1130
Author(s):  
Otto L. Stiefvater

Abstract The pure rotational spectra of molecules in 21 vibrationally excited states of the heterocyclic compound furazan (C2H2N2O) have been detected and studied by DRM microwave spectroscopy. Rotational parameters are reported for the 12 fundamental levels below 1500 cm-1 , and the contri-butions from 10 vibrational modes to the effective rotational constants and to the inertia defect of furazan are calculated.


1974 ◽  
Vol 29 (9) ◽  
pp. 1335-1344 ◽  
Author(s):  
M. Kuhler ◽  
L. Charpentier ◽  
D. Sutter ◽  
H. Dreizier

The microwave spectrum of CH3SS CD3 was investigated in the range of 5 -40 GHz. Rotational spectra in different states of the S-S-torsion were assigned. The methyl torsion fine structure of these spectra was measured and compared with calculations based on a Hamiltonian formulated for a model with two internal degrees of freedom, the methyl and S-S-torsion.


2003 ◽  
Vol 81 (12) ◽  
pp. 1419-1425 ◽  
Author(s):  
X -L Wu ◽  
B -C Gou ◽  
F Wang

Energies and fine-structure corrections for the doubly excited 3Pe and 3De states of the helium atom are calculated using the Rayleigh–Ritz variational method and the saddle-point variational method with a multiconfiguration-interaction function. The relativistic and mass polarization corrections are included. The oscillator strengths, transition rates, and wavelengths are also calculated. The doubly excited states are grouped into Rydberg series labeled by the quantum numbers K, T, and A to display the systematic regularity along the series. The results are compared with the theoretical and experimental data in the literature. PACS Nos.: 31.15.Pf, 31.25.Jf, 32.70.Cs


1983 ◽  
Vol 38 (12) ◽  
pp. 1309-1319 ◽  
Author(s):  
Yoshiaki Sasada

Abstract The rotational spectra of 3-bromothiophene in the excited states of two vibrational modes were observed and the rotational constants, the centrifugal distortion constants, and the nuclear quadrupole coupling constants were determined. The wave numbers of the two vibrational modes were evaluated to be 210 cm-1 and 320 cm-1 by measuring relative intensities of the ground and excited vibrational transitions. Variations in the inertia defect for each of the vibrational modes are compared with the results of the approximate calculation.


1976 ◽  
Vol 31 (7) ◽  
pp. 840-846
Author(s):  
F. Scappini ◽  
H. Dreizler

Abstract The microwave spectra of acetyl cyanide, CH3COCN, in the ground and in the two lowest excited states have been investigated. The rotational constants and the quadrupole coupling constants have been evaluated for all these states. The internal rotation parameters have been refined with respect to previous works. Evidence for a rotation-torsion -vibration interaction has been found in the spectra of the excited states.


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