E. Whalley

Infrared Spectra of Methanol and Deuterated Methanols in Gas, Liquid, and Solid Phases

The infrared spectra of CH3OH, CH3OD, CD3OH, and CD3OD in the five phases gas, liquid, vitreous solid, α‐crystal, and (except perhaps for CD3OH and CD3OD for which the solid‐solid transitions have not been studied) β‐crystal have been recorded in the range 4000 to 300 cm−1. The Raman spectrum of liquid CD3OH has been recorded. A complete assignment of the internal modes is given, which differs somewhat from previous assignments for the CH3 bending and rocking vibrations. No significant difference in spectrum occurred between the α‐crystal and β‐crystal phases. Under the full symmetry of the β‐phase determined by x‐ray diffraction only one OH out‐of‐plane bending band should occur. Two bands are observed, and it is concluded that the carbon and oxygen atoms in one chain are not coplanar, as is required by the symmetry determined by x‐ray diffraction [K. J. Tauer and W. N. Lipscomb, Acta Cryst. 5, 606 (1952)], but that the chains are puckered and the x‐ray symmetry arises because the puckered chains are irr...

Absorptivity of Ice I in the Range 4000–30 cm−1

The absorbance of several samples of ice Ih has been measured in the range 4000–30 cm−1, and scaled to that of a particular film of unknown thickness. The thickness of the film has been calculated by two methods, first from the known absorptivity at 4940 cm−1, and second by equating the appropriate Kramers–Kronig integral to the known infrared contribution to the microwave refractive index. The two thicknesses agreed well and allowed the absorptivity to be obtained in the range 4000–30 cm−1. The complex refractive index and permittivity and the normal incidence reflectivity have been calculated from the absorptivity. About three‐quarters of the infrared contribution to the microwave refractive index is caused by the translational lattice vibrations and about 15% by the rotational vibrations; the O–H stretching bands which absorb very strongly contribute relatively little. The maximum of the density of states in the transverse acoustic branch is at 65 cm−1 rather than below 50 cm−1 as reported earlier. Bel...

Infrared Spectra of Ices Ih and Ic in the Range 4000 to 350 cm—1

The infrared spectra of Ice Ih made from H2O, D2O, a mixture of 95% H2O and 5% D2O, and a mixture of 5% H2O and 95% D2O, and of Ice Ic made from H2O, D2O, and a mixture of 95% H2O and 5% D2O, have been recorded in the region 4000 to 350 cm—1 using low‐temperature mulling techniques developed in these laboratories. The Ice Ic was made by transformation of Ices II and III, and was authenticated by its x‐ray diffraction powder pattern. The spectra of Ices Ih and Ic are identical within experimental error. The spectra of Ice Ih, while similar in their main features to those reported by earlier workers, differ significantly in detail, probably largely because much of the previous work, particularly on D2O ice, has been done with partly vitreous ice. The usual interpretation of the bands in terms of the v1, v2, v3, and vR vibrations of isolated molecules is greatly oversimplified because intermolecular coupling is important. There are at least six (five infrared and one Raman) bands due to O—D stretching vibrat...

Reanalysis of the density of liquid water in the range 0–150 °C and 0–1 kbar

The change of density of liquid water under pressure has been calculated from the speed of sound u by fitting u−2 as a polynomial in temperature and pressure, integrating with respect to pressure, and allowing for the difference between isothermal and adiabatic compressions. By comparing calculations done by different methods on the same data and on different data it appears that the densities so obtained are accurate to about 20 ppm at 1 kbar. These densities are about 100 ppm greater than the densities obtained by us some years ago by direct measurement of the compressions in the range 0–150 °C and 0–1 kbar relative to a stainless steel vessel. It seems likely that the compressibility of the vessel used in this work is too high by about 0.1 Mbar−1. A correction to the compressibility of the vessel is proposed to bring the densities in the range 0–100 °C and 0–1 kbar into agreement with the values from the speed of sound. The same correction should apply in the range 100–150 °C, and the corrected values ...

Optical Spectra of Orientationally Disordered Crystals. II. Infrared Spectrum of Ice Ih and Ice Ic from 360 to 50 cm−1

The far‐infrared spectra in the range 360–50 cm−1 of ice Ih and ice Ic made from H2O and from D2O, and of vitreous ice made made from H2O have been investigated. The spectra are due to essentially purely translational vibrations, and have been interpreted using the theory of the spectra of orientationally disordered phases developed in the preceding paper. There are peaks at 229.2 and 164 cm−1 that are due (in ice Ic) to maxima in the density of vibrational states due to the transverse optic and longitudinal acoustic vibrations, respectively, and a shoulder at 190 cm−1 due to the maximum in the longitudinal optic vibrations. There is also a peak just below 50 cm−1 in the spectrum of optical density divided by the square of the frequency that is due to the maximum in the transverse acoustic vibrations. Corresponding assignments are proposed for ice Ih. The Raman spectrum can in principle yield similar information, and agrees with the infrared spectrum in so far as the measurements can be compared.Some of t...

Optical Spectra of Orientationally Disordered Crystals. I. Theory for Translational Lattice Vibrations

There is a class of crystals in which the molecules are arranged on or near regular positions in space, but are irregularly oriented. The irregular orientation of the molecules frequently perturbs only slightly the translational lattice vibrations of the crystal, that would be perfectly periodic if the irregular orientation were absent. For a first approximation, then, the crystal can be considered to have mechanically regular vibrations. In particular, any normal vibration can be described in terms of a wave vector k that is the wave vector of the dominant Fourier component of the vibration. The irregular orientation of the molecules will cause the dipole‐moment change due to a displacement of a particular molecule to depend in magnitude and direction upon its own orientation and upon the orientation of its neighbors. The crystal is thus in a sense electrically irregular.The theory of the optical spectra due to the translational lattice vibrations of these mechanically regular, electrically irregular cry...

Transformations of Ice II, Ice III, and Ice V at Atmospheric Pressure

The transformations that occur in ices II, III, and V at atmospheric pressure when they are heated from liquid‐nitrogen temperature have been examined by simple thermal analysis and by x‐ray diffraction. They transform first to cubic ice I (ice Ic). The rate of transformation of ices II and III depends upon the temperature, and that of ice II probably depends upon its thermal history. The temperature dependence of the rate for ice V, and the history dependence of the rate for ices III and V were not examined. Ice Ic has previously been made only in small quantities; it can now be made in as large quantities as required by transformation of the high‐pressure ices. The transformation of ice Ic to ordinary hexagonal ice (ice Ih) has also been examined. The rate depends markedly on the thermal history of the sample and this may help to explain the apparently inconsistent rates that have been reported by various workers.

Infrared Spectra of Ices II, III, and V in the Range 4000 to 350 cm—1

The infrared spectra of Ices II, III, and V between 4000 and 350 cm—1 have been obtained. The ices were made at appropriate pressures and temperatures, cooled under pressure to liquid‐nitrogen temperature, and removed from the pressure vessel. Mulls were made near liquid‐nitrogen temperature using isopentane or perfluoropropane as mulling agents, and the spectra of the mulls at ∼100°K were recorded. The spectra of ices made from H2O, D2O, 5% H2O in D2O, 5% D2O in H2O, and, for Ices II and III, 1% D2O in H2O were obtained. In general features, the spectra of pure H2O and D2O Ices II, III, and V are similar to those of Ice I. For most bands there is a shift of frequency from that in Ice I towards the vapor frequencies, but the shift is small compared with the shift between Ice I and the vapor. Ices II, III, and V are therefore essentially fully hydrogen bonded and are probably four coordinated. This agrees with a proposed structure for Ice III.In Ices II and III the bands due to the O–H and the O—D stretchi...

Ice IX: An Antiferroelectric Phase Related to Ice III

The dielectric properties of ice III in the frequency range 10−1 to 105 cps have been measured down to − 160°C. There is a gradual transition from the orientationally disordered III to an orientationally ordered and probably antiferroelectric phase, which is designated IX, starting at about − 65°C and reaching completion at about − 108°C. An arrangement of the hydrogen atoms in ice IX is proposed. The amplitude of the orientational polarization decreases continuously through the transformation region although the relaxation time is close to the value extrapolated from previous measurements in the disordered phase. The limiting high‐frequency dielectric constant of the dispersion decreases with decreasing temperature. The cause of this behavior, which is unusual for molecular crystals, is undoubtedly that the polarization of the lattice vibrations contributes a large part of the high‐frequency dielectric constant. This contribution decreases with decreasing temperature because the decreasing anharmonic int...

High‐density amorphous ice. III. Thermal properties

The thermal properties of high‐density amorphous ice, which is made by ‘‘melting’’ ice I at 77 K by applying a pressure of ∼10 kbar, have been measured in an automated Tian–Calvet calorimeter. The samples were heated from 78 to 270 K at a rate of 10 K h−1 and heat amounting to 544, 1425, and 35.5 J mol−1 was evolved in one run at the sharp transitions from high‐density to low‐density amorphous ice, from the low‐density amorph to ice Ic, and from ice Ic to Ih, respectively. In addition, heat was spontaneously evolved by the high‐density amorph before the transition, and by the sample over a range of ∼50 K around the temperature of the transition from ice Ic to Ih.