Kenji Kuratani

Rotational Isomerism in Chloroacetone

Raman spectra of chloroacetone were measured in the liquid and solid states and in solutions. Infrared absorption spectra of this substance were measured in the gaseous, liquid, and solid states and in solutions. The temperature dependence of the intensity of the Raman lines and of the absorption bands were measured in the liquid state. From the experimental results together with the dipole data it was concluded that chloroacetone exists in two molecular forms in the liquid and gaseous states and in one form in the solid state. The less stable form in the liquid state becomes much more abundant than the other form in the gaseous state. Some considerations on the nature of hindering potential of internal rotation have been made.

Rotational Isomers of Chloroacetyl Chloride, Bromoacetyl Chloride, and Bromoacetyl Bromide

The Raman spectra of chloroacetyl chloride, bromoacetyl chloride, and bromoacetyl bromide have been measured in the solid and liquid states. The infrared absorption spectra of these substances have also been measured in the liquid and the gaseous states. From the experimental results it has been concluded that there are two rotational isomers in the liquid and gaseous states and only one of them persists in the solid state. The temperature dependence of the intensity of the infrared absorption in the gaseous state has also been studied, and the energy difference between these two isomers has been found as 1.0±0.1 kcal/mol for bromoacetyl chloride and 1.9±0.3 kcal/mol for bromoacetyl bromide.The calculation of the normal vibrations and of the product rule has been made for various configurations of rotational isomers, and it has been shown that the more stable form is the trans form (or nearly this one) with regard to the two halogen atoms. The less stable form is considered to have an azimuthal angle betw...

Erratum: Shock‐Wave Study of Vibrational Energy Exchange between Diatomic Molecules

The relaxation equation of the vibrational energy for a mixture of two diatomic gases is solved under the condition of Landau–Teller, considering the translation–vibration energy transfer (T–V) processes as well as the vibrational energy exchange (V–V) process. The solution shows that the relaxation of each of the component molecules proceeds as if it has two relaxation times. At the starting point of the relaxation process, both of the components begin to relax with their respective T–V relaxation rates, and then, the relaxation rate of one component, which has a smaller T–V relaxation time, decreases gradually, while the rate of the other component increases. Finally, both the components relax with the same rate toward their equilibrium states. The extent of coupling between the T–V processes of the two components is determined by the rate of the V–V process and by the concentration of two species in the mixture. Based on the preceding analysis, the vibrational relaxations of CO in CO–N2, CO–C2, CO–D2, ...

Infrared Absorption Investigation on the Rotational Isomerism of 1,1,2‐Trichloroethane

The energy difference between the rotational isomers of 1,1,2‐trichloroethane has been determined in the gaseous and liquid states by the infrared absorption measurements. In the solid state, only one of the rotational isomers has been found to be stable. The different behavior in rotational isomerism between 1,1,2‐trichloroethane and 2‐methylbutane, both having the same skeletal configuration, has been explained in terms of the difference in the electrostatic part of the hindering potential.

In-plane normal vibrations of methanol

Abstract Infra-red spectra of CH3OH and CH3OD have been measured in the vapour and liquid states and in non-polar solutions. Normal modes of vibrations of CH3OH, OH3OD, and CD3OH have been calculated. Based on the results, the complete assignment of the A vibrations of methanol have been made.

Infrared and Raman Spectra of 1,1,2,2‐Tetrachloroethane; Calculation of Normal Vibrations

Infrared spectra of 1,1,2,2‐tetrachloroethane have been measured in the gaseous, liquid, and solid states and in solutions. Raman spectra of the same substance have been observed in the liquid and solid states. From the experimental results the equilibrium molecular forms of the rotational isomers have been determined. The normal vibrations of the molecule in the trans‐ and gauche‐forms have been calculated as an 8‐body problem, and the assignment of the observed infrared and Raman frequencies in all the states of aggregation has been made.

Excitation and quenching of sodium atoms behind a shock wave

Abstract The electronic excitation temperatures of sodium atoms involved in argon, nitrogen-argon and carbon monoxide-argon mixtures have been observed by the simultaneous measurement of sodium D-line emission and absorption behind the shock wave. In shock-heated argon, the intensity of emission rises very fast after the passage of the shock front, and the measured temperature is 60° to 1000°K lower than that calculated from the shock velocity. However, the experimental results in the one per cent nitrogen-99 per cent argon mixture show that D-line emission becomes intense gradually behind the shock front and attains a steady value. The temperature observed in the steady region agrees with the calculated one. These results can be explained in terms of exciting or quenching efficiency of gaseous particles in collisions with sodium atoms. The calculation of collisional frequency for quenching Na( 2 P) has been done, and it is concluded that molecular collisions with sodium atoms are dominant in the shock wave in argon, nitrogen-argon or carbon monoxide-argon mixtures in the temperature range of 2 000° to 3 000°K, and that the effective quenching cross section of argon in collisions with sodium atoms is smaller than 10 −20 cm 2 . The profile of emission intensity behind the shock front gives a vibrational relaxation time in nitrogen-argon or carbon monoxide-argon collisions as proposed by Gaydon and Hurle.

The Infrared Dichroism of Diketopiperazine

The absorption of polarized infrared radiations by diketopiperazine crystal has been measured in the wavelength region from 2.8 to 15μ. From the observed infrared dichroism the assignment of the absorption bands has been made.