Gerald L. Carlson

Infrared spectra of inorganic ions in the cesium bromide region (700–300 cm−1)

Abstract The infrared spectra from 300–880 cm−1 of 208 inorganic substances are reported. Nearly all are salts containing polyatomic ions. Spectral curves are presented for 140 of the compounds, and a list of characteristic frequencies is given for twenty ions. Among other matters discussed are: (a) the non-reproducibility of some of the spectra, and reasons for this, (b) absorption due to the torsional oscillation of water molecules, and (c) some vibrational assignments for MnO4−1 and CrO42−1.

Far infrared spectra of dimeric and crystalline formic and acetic acids

Infrared spectra of gaseous (HCOOH)2, (HCOOD)2, (CH3COOH)2, and (CD3COOH)2 have been obtained over the range of 33–400 cm−1. All of the expected low frequency, infrared-active “hydrogen bond” fundamentals were located and assigned. The spectra of crystalline, polymeric HCOOH and HCOOD show some structure in the 250 cm−1 region but do not verify the interpretation of the earlier Raman data. For crystalline CH3COOH only a single intense band at 198 cm−1 was observed.

The measurement of conformational equilibria via the infrared studies of 1,1-dibromo-3-fluorobutadiene-1,3 and 1,1-dichloro-3-fluorobutadiene-1,3

Abstract In the analysis of conformational equilibria it is customarily assumed that the absorption coefficients of the infrared bands are temperature independent. In this study a convenient test of this assumption is proposed which also provides for the immediate calculation of the equilibrium constant. The method is applied to the s-trans ⇌ skew equilibria of 1,1-dibromo-3-fluorobutadiene-1,3 and 1,1-dichloro-3-fluorobutadiene-1,3. For the former compound ΔH = 844 ± 100 cal/mole and ΔS = 3.5 ± 1 e.u. and for the latter ΔH = 706 ± 100 cal/mole and ΔS = 2.3 ± 1 e.u. in CS2 solvent. Some approximations used in previous studies axe briefly discussed and the present method is applied to the data presented in one of these reports.

Infrared and Raman spectra of chromyl chloride

Abstract The infrared spectrum of CrO 2 Cl 2 , a deep red liquid, has been measured from 120–3000 cm −1 . Six Raman lines have been obtained by excitation with the D -lines of potassium. The fundamental frequencies are, for C 2v symmetry: a 1 = 981, 465, 356, 140; a 2 = 224; b 1 = 995, 211; b 2 = 496, 257. The results agree well with the very recent work on the Raman spectrum by Stammreich et al . Thermodynamic properties have been calculated at four temperatures.

The vibrational spectrum ot Si(NCS)4

Abstract The infrared absorption spectrum from 75 to 4000 cm −1 and the Raman spectrum with polarizations have been determined for Si(NCS) 4 . The data are best interpreted on the basis of a tetrahedral model which requires linear Si—NCS groups, in agreement with earlier results for Si(NCO) 4 . Attempts to prepare Ge(NCS) 4 were unsuccessful.

Far-Infrared Transmission of Commercially Available Crystals and High-Density Polyethylene

Recently, far-infrared spectrometers and interferometers have become available to many researchers and laboratories. With this new interest in the low-energy region of the spectrum, we thought it useful to publish a collection of transmission curves of commercially available crystals and high-density polyethylene so that choices could be made for cell windows and filters for work in this region.1

The vibrational spectrum of trans-vinylene diisocyanate

Abstract The infrared spectrum from 75–4000 cm−1 and the Raman spectrum (with polarizations) are reported for the new compound trans-vinylene diisocyanate, OCNCHCHNCO. Assignment of the fundamental vibrational frequencies on the basis of a trans planar C2h model have been made. The ultraviolet spectrum was found to consist of a single band at 2250 A with an absorptivity of 19,770 liter mole−1 cm−1.