Ultrasonic Relaxation in Rotational Isomers

1959 ◽  
Vol 30 (1) ◽  
pp. 304-307 ◽  
Author(s):  
Joseph H. Chen ◽  
A. A. Petrauskas
Keyword(s):  
Rotational Isomers ◽  
Ultrasonic Relaxation

Ultrasonic relaxation processes in liquid triethylamine

1956 ◽  
Vol 237 (1209) ◽  
pp. 233-244 ◽  
Keyword(s):  
Activation Energy ◽  
Energy Barrier ◽  
Ultrasonic Waves ◽  
Relaxation Processes ◽  
Activation Energy Barrier ◽  
Temperature Range ◽  
Rotational Isomers ◽  
Velocity Of Propagation ◽  
Ultrasonic Relaxation ◽  
The Difference

Measurements have been made of the velocity of propagation and the absorption of ultrasonic waves in liquid triethylamine over the temperature range 25 to 70° C and at frequencies of approximately 23, 66, 107, 148 and 192 Mc/s. The absorption results demonstrate the existence of a relaxation process which is attributed to the perturbation by the sound wave of an equilibrium between rotational isomers. The activation energy barrier and the difference in energy between the states are evaluated from an analysis of the results. The calculated dispersion of velocity is less than 1%. Values of the specific heat of triethvlamine are required in the analysis and are given in the paper for the temperature range 25 to 60°C. The results are discussed in the light of other measurements concerned with rotational isomers.

Ultrasonic relaxation and rotational isomerism in liquid sym -tetrabromoethane and tri- n -butylamine

1958 ◽  
Vol 244 (1239) ◽  
pp. 558-572 ◽  
Keyword(s):  
Potential Energy ◽  
Ultrasonic Waves ◽  
Rotational Isomerism ◽  
State Model ◽  
Energy Parameters ◽  
Rotational Isomers ◽  
Infra Red ◽  
Molecular Interpretation ◽  
Ultrasonic Relaxation ◽  
Two State Model

Measurements have been made of the absorption of ultrasonic waves at frequencies in the range 10 to 200 Mc/s in sym -tetrabromoethane from 0 to 60°C and in tri- n -butylamine from – 60 to 60°C. For both liquids the absorption is determined in part by a relaxing process which is associated with the equilibrium between rotational isomers. The results for sym -tetrabromoethane are compared with infra-red data obtained by Kagarise (1956), and the potential energy barriers hindering rotation between the gauche and trans forms of the molecule are determined from the measurements. The energy parameters associated with a two-state model for tri- n -butylamine are evaluated and compared with previous results for triethylamine. This leads to a molecular interpretation of the isomeric configurations responsible for the observed relaxation.

ULTRASONIC RELAXATION IN α-SULFUR

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-611-C6-613
Author(s):  
M. Boissier ◽  
R. Vacher ◽  
B. Perrin
Keyword(s):  
Ultrasonic Relaxation

LOW TEMPERATURE ULTRASONIC RELAXATION IN A DILUTE Ta-H ALLOY

1985 ◽  
Vol 46 (C10) ◽  
pp. C10-87-C10-90 ◽  
Author(s):  
K. R. MASCHHOFF ◽  
A. V. GRANATO
Keyword(s):  
Low Temperature ◽  
Ultrasonic Relaxation
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