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Atom polarisations, apparent dipole moments and dielectric relaxation times of 1,4-benzoquinone in various solvents were determined together with those of some of its derivatives in benzene solution. Solvent effects on the apparent dipole moments of 1,4-benzoquinone and its derivatives were examined in comparison with the absorption spectra in the submillimetre region.

Dielectric constants and losses at the microwave frequency of 96.52 GHz have been measured at 25°C for methyl, ethyl, n-butyl, isobutyl, s-butyl, t-butyl, n-amyl, isoamyl, n-hexyl, and n-octyl acetates in benzene solutions. Static dielectric constants, refractive indices and densities have also been measured. The effective mean relaxation times of normal alkyl acetates increase with increasing chain length of the alkyl radical, eventually approaching a steady value. The distribution parameters α of all these molecules seem to have appreciable values which may be due to various segment orientations by internal rotation.

The dielectric constants and losses of diphenylene dioxide, phenoxathiin, thianthrene, xanthene and pheno-thiazine have been measured in dilute solution of benzene at the millimeter-wave frequency of 100 GHz at 20 °C. Diphenylene dioxide is found to have a very small dielectric relaxation time which is associated with the change in dipole orientation by the intramolecular change (butterfly motion). The dipole moment of this molecule is small but not considered to be zero. Similar to thianthrene, which has a folded structure about the S–S axis, diphenylene dioxide is also folded about the O–O axis or can easily have a folded structure. Phenoxathiin and the other two molecules have a folded structure and the dielectric relaxation times (at 100 GHz) reveal the effect of the butterfly-flapping motion associated with the barrier height for this internal motion.

Far infrared spectra from 400 to 30 cm-1of triglycine sulfate and its deuterated analogue were measured and the bands due to the librational modes of glycine molecules were identified. Polarized Raman spectra below 300 cm-1of triglycine sulfate single crystals were measured and the symmetry species of the observed lattice vibrations were determined. Temperature dependence of the lattice vibrations was examined. Significant changes were detected in both infrared and Raman spectra on crossing the Curie temperature, indicating a flipping motion of glycine I in the paraelectric phase and suggesting the ferroelectric transition in triglycine sulfate to be of an order-disorder type.

The dielectric constants and losses of 2-propanol and its mixtures with benzene, chlorobenzene, 1,4-dioxane or pyridine and 2-methylpropanol or 2-butanol and their mixtures with benzene or pyridine have been measured in the frequency range of 0.35–2.1 GHz at 25.0 °C. Concentrations of alcohols are 1–0.6 mol fractions of the mixtures. The principal relaxation times and the Kirkwood correlation factor gwere evaluated. Variation of the principal relaxation times against the concentrations of these branched alcohol mixtures is not much different from that of normal alcohol mixtures. The gfactor decreases almost monotonously with increasing amount of solvent exception being found in case for propanol–benzene mixtures.

The dielectric constants and losses of 1-propanol and its mixtures with benzene, chlorobenzene, 1,4-dioxane or pyridine, and 1-butanol and its mixtures with benzene or pyridine have been measured in the frequency range of 0.35–2.1 GHz at 25.0 °C. Concentrations of alcohols are 1–0.6 mol fraction of the mixtures. Densities and refractive indices have also been determined. The dielectric data were used to calculate the relaxation times of the alcohols. The Cole-Cole plots for these systems showed Debye-type semicircles in lower frequencies where the principal relaxation of alcohols dominates. Deviations from the semicircle, however, have been observed in the region of upper frequencies, where the second dispersion of alcohol, the dispersion of solvent itself and of hydrogen-bonded species between alcohol and solvent may occur. The principal relaxation times of alcohols calculated from the data of lower frequencies change with concentration in two different manners by solvents, and this difference is due to whether the solvent has hydrogen-bonding capacity or not, and does not depend upon the dielectric constant and/or the polarity of the solvent.

Infrared spectra of Li2SO4·H2O and Li2SO4·D2O have been measured from 4000 to 30 cm−1at room temperature and liquid-nitrogen temperature. Librational bands of the water of crystallization have been observed and the modes of libration are discussed. The normal coordinate analysis of the crystal as a whole has been performed and the observed bands are interpreted. Translational bands of H2O and librational bands of SO4are also discussed.

Infrared spectra of HgNH2Cl and HgNH2Br and the Raman spectrum of HgNH2Cl have been measured in the region from 4000 cm−1to 30 cm−1. Effects of changing the X(X=Cl,Br) ion were observed mainly in N–H stretching bands and in lattice vibrations. Calculations of normal frequencies were carried out using a force field which includes inter-molecular forces. An assignment of the lattice vibrations was proposed and the force constants were also calculated. The force constants of the inter-molecular hydrogen bonds N–H···Cl and N–H···Br were obtained as 0.212 mdyn/Å and 0.142 mdyn/Å, respectively.

Polarized far infrared spectra from 400 to 30 cm−1of benzoic acid single crystals have been measured. Three bands polarized parallel to the C2sscrew axis bwere observed at 104, 86, and 62 cm−1, and three bands polarized parallel to the a-axis at 106, 76, and 65 cm−1. The lattice vibrations of benzoic acid have been calculated assuming the rigidity of the molecule during the lattice vibrations and applying a simple force field. The bands at 104, 86, and 62 cm−1were assigned to the rotational vibrations of Ausymmetry species: the O–H···O stretching, the ring torsional and the O–H···O out-of-plane bending modes, respectively, and the bands at 106, 76, and 65 cm−1to those of Busymmetry species. The force constant K(O···H) related to the hydrogen bonds in the cyclic dimer was calculated to be 0.35 mdyn/Å.

This paper gives details of the equipment and the method of the measurement at 100 GHz. Dielectric constants and losses are measured at this frequency for ten organic molecules in benzene and four (aniline, phenol, and its derivatives) both in benzene and in dioxane. A majority of the molecules studied are of non-rigid configuration. Discussion is given of the relaxation times and the mechanism of internal rotation involved. Hydrogen bonding effects in aniline, phenol, and its derivatives are also discussed.

Experiments to confirm Kubo’s conclusion on the complex formation of 1,2-dichloroethane with benzene were carried out following his procedure. Dielectric measurements were carried out with inert solvents hexane and cyclohexane. The interactions between 1,2-dichloroethane and each of the compounds toluene and p-xylene were also studied with inert solvents hexane, cyclohexane, and carbon tetrachloride. The results are discussed in relation to complex formation.