A new sputtering apparatus

The writer, in sputtering a large number of mirrors, has found that the apparatus and methods to be described have several advantages, particularly where very large and perfect mirrors are desired. The accompanying diagram will be self explanatory, and the dimensions given have been found convenient for mirrors up to 10 cm diameter

Note on the Spectra of the Disubstituted Acetylenes and of the Mustard Oils

It has been observed that in the Raman spectra of many disubstituted acetylenes the line corresponding to the so-called C≡C frequency is split into two components of not greatly different intensity (1), though this is not the case in the monosubstituted compounds. In the mustard oils the C≡N Raman line is double (2), and in allyl mustard oil (3), the one substance which appears to have been studied with sufficient dispersion, the corresponding infrared band shows definite indications of splitting into two components. This doubling is not observed in the organic thiocyanates. These facts have caused some speculation so far appear never to have received a satisfactory explanation. The presence of two fundamentals in the 2200 cm^-1 region appears quite impossible for most of the molecules showing the doubling, and on the other hand the coexistence of two forms of molecule with slightly different frequencies appears unlikely, especially in the case of the acetylenes. Consequently the author proposes an explanation involving a Fermi resonance interaction between the C≡C or C≡N fundamental, as the case may be, and the overtone of a certain other vibration of approximately one-half or one-third the frequency

The Relation Between the Energy of a Hydrogen Bond and the Frequencies of the O[Single Bond]H Bands

It has previously been pointed out (1) that there appears to be a relation between the energy of a hydrogen bond and the shift of the frequency of the O-H bands which accompanies the formation of the bond. Recently additional data have been obtained in this laboratory (2,3) which confirm the existence of this useful relation and it seems worth while to discuss them in this connection. The data here presented all relate to linkages in which a hydroxyl hydrogen is concerned, though the atom to which it is weakly bound may be oxygen, chlorine, or carbon in an aromatic ring. It is surprising that the same connection between energy and frequency shift should be found in these various cases but such appears to be the fact. For other types of bond, for example those involving the hydrogen of an amino group, a slightly different relation may well be expected

Two devices facilitating spectrometry in the far infrared

In spectrometric investigations in the infrared two principal difficulties are the extremely small energy available in the long waves, and the relatively great intensity of the near infrared. This latter is of particular importance in using an echlette grating which reflects the short waves with great intensity in high orders. The arrangement here described was devised to overcome both of these inconveniences

A Microilluminator for the Study of the Infrared Spectra of Small Samples at Low Temperatures

An instrument is described which combines the functions of a reflecting microscope and a low temperature cell. It permits infrared absorption spectra to be obtained on single microcrystals at low temperatures, using polarized radiation

Infrared Absorption Associated with Strong Hydrogen Bonds

Several investigators have proposed that there exists a more or less unique relation between the O-O distance in O-H-O hydrogen bonds and the shift of O-H vibrational frequency. [1-5] However, the meager intensities of some bands which have been ascribed to this vibration (notably in nickel dimethyl-glyoxime and potassium dihydrogen phosphate) have made us a little skeptical of the correlation inthe case of very short, and possibly symmetrical, hydrogen bonds

The Polarized Infrared Spectrum of Potassium Bifluoride at –185°C

Observations on the reflection spectrum of potassium bifluoride have recently been reported [1] which appear to confirm the symmetrical linear structure of the bifluoride ion in this crystal. Some time ago absorption spectra of single crystals of KHF2 using polarized infrared radiation were obtained in this laboratory which both confirm this work and supplement it. Owing to the improved resolution of complex absorption regions which we obtained at low temperatures it seems worthwhile to present these results briefly. The spectrum is possibly unique in the wealth of combination and overtone bands which arise from a crystal of structure so simple that a detailed interpretation may be anticipated

The infrared spectra of HOCl and DOCl

We have recently observed the spectra of hydrogen hypochlorite and deuterium hypochlorite in the region 1-15μ as part of a general program of study of simple molecules. Since, so far as we are aware, no spectroscopic data has heretofore been reported on these substances, the preliminary results are of sufficient interest to be presented at this time

The infra-red spectrum and molecular structure of HNCS

From an examination of the microwave spectra of four isotopic species of isothiocyanic acid, Beard and Dailey (1) recently obtained the following values for the molecular parameters in the ground vibrational state

An Absorption Band of Formaldoxime at lambda9572

The third harmonic of the O [Single Bond] H band in formaldoxime vapor has been found to lie at lambda9572 (10,444.1 cm^—1) and under high dispersion has been resolved and found to resemble a parallel band of a symmetric rotator. Owing to the weakness of the lines near the center of the band a definitely unique rotational analysis could not be made but the harmonic mean of the two larger moments of inertia appears to lie between the limits 73.3 and 76.6×10^—40 g cm^2. The hydroxyl hydrogen does not rotate freely and indeed its torsional oscillation appears not to have a very low frequency. It is not possible to locate this hydrogen uniquely until other parameters of the molecule have been determined by electron diffraction. The possible effect of resonance on the O [Single Bond] H frequency is discussed