Internal rotation of methyl group in electronically excitedo-andm-ethynyltoluene: New correlation between the Hammett substituent constant σmand rotational barrier change

2011 ◽  
Vol 134 (8) ◽  
pp. 084311 ◽  
Author(s):  
Sei-ichi Tanaka ◽  
Katsuhiko Okuyama
Keyword(s):  
Internal Rotation ◽  
Rotational Barrier ◽  
Substituent Constant ◽  
Methyl Group ◽  
New Correlation

Microwave spectrum: Barrier to the internal rotation of the methyl group of methyl cyanate and its molecular structure

1995 ◽  
Vol 345 ◽  
pp. 189-195 ◽  
Author(s):  
Takeshi Sakaizumi ◽  
Mikio Namikawa ◽  
Osamu Ohashi
Keyword(s):  
Molecular Structure ◽  
Internal Rotation ◽  
Microwave Spectrum ◽  
Methyl Group

Mikrowellenspektrum und Struktur von Fluortribromsilan und Methyltribromsilan

1968 ◽  
Vol 23 (11) ◽  
pp. 1819-1821 ◽  
Author(s):  
M. Mitzlaff ◽  
R. Holm ◽  
H. Hartmann
Keyword(s):  
Least Squares ◽  
Internal Rotation ◽  
Kcal Mole ◽  
Rotational Constants ◽  
Methyl Group ◽  
Microwave Spectra ◽  
Group A

The microwave spectra of SiFBr3 and CH3SiBr have been investigated in the region from 30 to 40 GHz. Assuming reasonable values for dSi-F, dSi-C and the methyl group a least squares analysis of the rotational constants yieldsdSi-Br ≮Br—Si—BrSiFBr3 (2,171 ± 0,001) A (111,36 ± 0,15)°,CH3SiBr3 (2,175±0,001) A (111,09±0,15)°.A barrier to internal rotation of about 1 kcal/mole is estimated by the intensity method.

The rotational barrier for methyl group dynamics in anhydrous sodium acetate

2002 ◽  
Vol 74 (0) ◽  
pp. s1351-s1353
Author(s):  
A.J. Moreno ◽  
A. Alegr�a ◽  
J. Colmenero ◽  
B. Frick
Keyword(s):  
Group Dynamics ◽  
Sodium Acetate ◽  
Rotational Barrier ◽  
Anhydrous Sodium Acetate ◽  
Methyl Group ◽  
Methyl Group Dynamics

Internal Rotation of the Methyl Group in them-Tolunitrile−Rare Gas Complexes

1996 ◽  
Vol 100 (24) ◽  
pp. 10037-10040 ◽  
Author(s):  
Masao Takayanagi ◽  
Ichiro Hanazaki
Keyword(s):  
Internal Rotation ◽  
Rare Gas ◽  
Methyl Group

Millimeter-Wave Spectrum of Ethyl Acetylene Centrifugal Distortion, Coriolis Interaction and Internal Rotation

1983 ◽  
Vol 38 (4) ◽  
pp. 447-451 ◽  
Author(s):  
J. Demaison ◽  
D. Boucher ◽  
J. Burie ◽  
A. Dubrulle
Keyword(s):  
Excited State ◽  
Internal Rotation ◽  
Plane Deformation ◽  
Wave Spectrum ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Coriolis Interaction ◽  
Methyl Group ◽  
First Excited State ◽  
Methyl Torsion

The rotational spectrum of ethyl acetylene has been investigated between 70 and 320 GHz. A Coriolis interaction has been found between the first excited state of the methyl torsion and the C - C = C in plane deformation. Splittings of transitions in the first excited torsional state show that the barrier hindering internal rotation of the methyl group amounts to 3271 cal/mole.

High Resolution Microwave Spectroscopy of Ethyl Vinyl Ether: Accurate Determination of the Methyl Top Internal Rotation Barrier

2000 ◽  
Vol 55 (5) ◽  
pp. 481-485 ◽  
Author(s):  
H. Dreizler ◽  
N. Hansen
Keyword(s):  
Internal Rotation ◽  
Vinyl Ether ◽  
Accurate Determination ◽  
Ethyl Vinyl Ether ◽  
Ethyl Vinyl ◽  
Methyl Group ◽  
Rotational Spectra ◽  
Internal Rotation Barrier ◽  
In Trans

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 .

Determination of a High Potential Barrier Hindering Internal Rotation in 2-Methylcyclopentanone and α-Methyl-γ-Butyrolactone by Microwave Fourier Transform Spectroscopy

1992 ◽  
Vol 47 (6) ◽  
pp. 761-764 ◽  
Author(s):  
J. L. Alonso ◽  
N. Heineking ◽  
H. Dreizler ◽  
N. Heineking ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Excited States ◽  
Fourier Transform Spectroscopy ◽  
Vibrationally Excited ◽  
Methyl Group ◽  
Internal Rotation Barrier ◽  
High Potential Barrier ◽  
Method Analysis

AbstractThe microwave spectra of α-methyl-γ-butyrolactone and 2-methylcyclopentanone have been reinvestigated using microwave Fourier transform spectroscopy. A-E splittings due to internal rotation of the methyl group have been observed in the ground and several vibrationally excited states for both molecules. From an internal-axis-method analysis of these splittings, values of the methyl group internal rotation barrier of 2.61 kcal mol-1 for α-methyl-γ-butyrolactone and 2.41 kcal mol-1 for 2-methylcyclopentanone have been obtained.

Structure and Barrier to Methyl Group Internal Rotation for (CF3)2CFCF2OCH3and Its Isomern-C4F9OCH3(HFE-7100)

2011 ◽  
Vol 115 (6) ◽  
pp. 1086-1091 ◽  
Author(s):  
G. S. Grubbs ◽  
S. A. Cooke
Keyword(s):  
Internal Rotation ◽  
Methyl Group
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