Rotational spectra, electric dipole moment and methyl group internal rotation barrier of 1,1,1-trifluoropropane

1997 ◽  
Vol 93 (7) ◽  
pp. 1291-1295 ◽  
Author(s):  
Sonia Antolínez ◽  
Juan C. López ◽  
Jose´ L. Alonso
1965 ◽  
Vol 20 (12) ◽  
pp. 1682-1686 ◽  
Author(s):  
Heinz Dieter Rudolph ◽  
Helmut Seiler

The microwave rotational spectrum of para-fluoro-toluene has been investigated in the region from 7 to 31 kmc/s. The three types of absorption lines to be expected in the case of a molecule of this type, i. e. with a very low sixfold barrier hindering the internal rotation of the methyl group, have been found: m=0, | m | ≠ 0, 3 n, | m | = 3 n. From the lines m=0 the rotational constants and the dipole moment, (1.96 ± 0.02) D, have been deduced; from the lines |m|=3 the internal rotation barrier could be calculated as V6=13.82 cal/mole. This V6 is compared with the values found for similar molecules.


1976 ◽  
Vol 31 (3-4) ◽  
pp. 374-380 ◽  
Author(s):  
W. U. Stieda ◽  
E. Tiemann ◽  
T. Törring ◽  
J. Hoeft

Abstract The rotational spectra of GeS and GeSe were measured in the frequency range of 66 GHz to 110 GHz with high precision. The breakdown of the Born-Oppenheimer approximation was observed for the rotational constant yol. With the known molecular 37-factor and the electric dipole moment the adiabatic part of the Born-Oppenheimer correction can be extracted from the primary observa-tion on y01. The adiabatic correction is very similar in both molecules but differs from the results in the earlier measurements on PbS.


2000 ◽  
Vol 55 (5) ◽  
pp. 481-485 ◽  
Author(s):  
H. Dreizler ◽  
N. Hansen

Abstract We have performed an investigation of the internal rotation of the methyl group in trans-cis ethyl vinyl ether by using molecular beam-Fourier transform Microwave (MB-FTMW) spectroscopy. Rotational spectra (up to J = 20) were recorded in the frequency region 4-19 GHz. Due to the internal rotation of the methyl group, some rotational transitions were split and the torsional barrier could be determined to V3 (CH3) = 1074.4(4) cm-1 .


2000 ◽  
Vol 104 (30) ◽  
pp. 6970-6978 ◽  
Author(s):  
Z. Kisiel ◽  
B. A. Pietrewicz ◽  
P. W. Fowler ◽  
A. C. Legon ◽  
E. Steiner

2001 ◽  
Vol 56 (9-10) ◽  
pp. 635-640 ◽  
Author(s):  
C. Thomsen ◽  
H. Dreizler

Abstract The rotational spectra of m-xylene, (CH3)2C6H4 and of m-xylene-d10, (CD3)2C6D4 have been recorded between 6 and 26.5 GHz using pulsed beam Fourier transform microwave spectroscopy. The clue for the assignment of the internal rotation multiplets was the inertial defect derived from the A1A1 species transitions. The rotational constants for m-xylene and m-xylene-d10 are A = 3572.1117(1) MHz / 2896.1195(17) MHz, B = 1761.8621(1) MHz / 1446.0236(15) MHz, C =1197.3943(2) MHz / 988.2357(7) MHz, the barrier to internal rotation of the two methyl groups are V3 = 53.7(16) J/mol / 39.8(5) J/mol, their moments of inertia were assumed to be I∞= 3.14 uÅ2 / 6.28 uÅ2.


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