CH-stretching overtone spectra and internal methyl rotation in 2,6-difluorotoluene

1997 ◽  
Vol 107 (3) ◽  
pp. 691-701 ◽  
Author(s):  
Chenxi Zhu ◽  
Henrik G. Kjaergaard ◽  
Bryan R. Henry
Keyword(s):  
Methyl Rotation

Methyl Rotation and Reentrant Metal-Insulator Transition in Deuterated (DMe-DCNQ1) 2 Cu System

2002 ◽  
Vol 379 (1) ◽  
pp. 101-106
Author(s):  
Yutaka Nishio ◽  
Yuko Mori ◽  
Sachie Sasaki ◽  
Koji Kajita ◽  
Shuji Aonuma ◽  
...  
Keyword(s):  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Methyl Rotation

Conformation and dynamics of alkylated bases within DNA: effect of methyl rotation

1995 ◽  
Vol 91 (2) ◽  
pp. 251 ◽  
Author(s):  
Leonor Cruzeiro-Hansson ◽  
Keith Parker ◽  
Julia M. Goodfellow
Keyword(s):  
Methyl Rotation

Internal methyl rotation and molecular structure of trifluorotoluenes: microwave rotational spectra of 2,3,4- and 2,4,5-trifluorotoluene

2020 ◽  
Vol 98 (6) ◽  
pp. 543-550 ◽  
Author(s):  
K.P. Rajappan Nair ◽  
Sven Herbers ◽  
Daniel A. Obenchain ◽  
Jens-Uwe Grabow
Keyword(s):  
Internal Rotation ◽  
Rotation Axis ◽  
Molecular Constants ◽  
Methyl Carbon ◽  
Rotational Spectra ◽  
Pulsed Jet ◽  
Principal Axes ◽  
The Moment ◽  
Centrifugal Distortion Constants ◽  
Methyl Rotation

The microwave rotational spectra of 2,3,4- and 2,4,5-trifluorotoluenes, along with all 13C isotopic species in natural abundance, have been recorded in the frequency range 8–27 GHz employing pulsed-jet Fourier transform microwave spectroscopy. The analysis of the spectra in the lowest torsional state has yielded the rotational constants, centrifugal distortion constants, three-fold barrier to methyl rotation, and the direction of the internal rotation axis in the moment of inertia principal axes systems of these trifluorotoluenes. For both molecules, the molecular constants of their eight isotopologues have been used to obtain the substitution rs structures of the ring and the methyl-carbon. The potential barriers hindering the internal rotation of the methyl top in 2,3,4- and 2,4,5-trifluorotluene are 2.5878(80) and 2.2809(23) kJ/mol, respectively.

scholarly journals Methyl-rotation dynamics in metal–organic frameworks probed with terahertz spectroscopy

2018 ◽  
Vol 54 (45) ◽  
pp. 5776-5779 ◽  
Author(s):  
Qi Li ◽  
Adam J. Zaczek ◽  
Timothy M. Korter ◽  
J. Axel Zeitler ◽  
Michael T. Ruggiero
Keyword(s):  
Terahertz Spectroscopy ◽  
Metal Organic Frameworks ◽  
Methyl Groups ◽  
Cryogenic Temperatures ◽  
Void Space ◽  
Metal Organic ◽  
Methyl Rotation ◽  
Rotation Dynamics

In ZIF-8 and its cobalt analogue ZIF-67, the imidazolate methyl-groups, which point directly into the void space, have been shown to freely rotate – even down to cryogenic temperatures.

scholarly journals Internal Rotation Analysis of the Ground State Microwave Spectrum of 2-Bromopropene

1984 ◽  
Vol 39 (7) ◽  
pp. 637-645
Author(s):  
E. Fliege ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Microwave Spectrum ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Methyl Rotation

The microwave spectrum of 2-bromopropene was reinvestigated with the use of microwave Fourier transform spectroscopy. For the two isotopic species CH3C79Br=CH2 and CH3C81Br=CH2 the bromine quadrupole coupling was determined with higher accuracy. The barrier hindering internal methyl rotation was obtained from the ground state.

scholarly journals Low barrier methyl rotation in 3-pentyn-1-ol as observed by microwave spectroscopy

2016 ◽  
Vol 114 (23) ◽  
pp. 3483-3489 ◽  
Author(s):  
Konrad Eibl ◽  
Raphaela Kannengießer ◽  
Wolfgang Stahl ◽  
Ha Vinh Lam Nguyen ◽  
Isabelle Kleiner
Keyword(s):  
Microwave Spectroscopy ◽  
Methyl Rotation

Local modes

2002 ◽  
Vol 80 (12) ◽  
pp. 1635-1642 ◽  
Author(s):  
Bryan R Henry ◽  
Henrik G Kjaergaard
Keyword(s):  
Atmospheric Chemistry ◽  
Molecular Conformation ◽  
Critical Role ◽  
Historical Background ◽  
Local Mode ◽  
Local Modes ◽  
Band Profile ◽  
Methyl Rotation ◽  
Insight Into

The historical background for the development of the local mode approach is reviewed, including the critical role of the radiation field. The harmonically coupled anharmonic oscillator model is described. Local modes have been used in the interpretation of XH stretching overtone spectra. These spectra can be used as sensitive probes of molecular properties such as bond length and molecular conformation. Examples of these spectral features are discussed. An intensity theory has been developed that permits the accurate calculation of relative and absolute overtone intensities. In molecules with low barriers to methyl rotation, torsional states contribute to the XH stretching band profile. A successful theoretical approach is presented that accounts for these effects and provides insight into the vibrational dynamics. The application of calculated local mode overtone spectra to atmospheric chemistry is discussed.Key words: local mode, overtone, vibrational intensity.

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