Low-temperature IR Spectroscopy Research Articles

Stretching vibrations of water in isotope-diluted ferroelectric potassium ferrocyanide trihydrate

A partially deuterated and a pure K 4Fe(CN) 6 · 3H 2O crystal have been investigated by low-temperature Raman and IR spectroscopy. Five unperturbed OH frequencies of the HDO molecules were found and are discussed in comparison with the corresponding OD frequencies obtained previously. The temperature behaviour of both unperturbed and perturbed OH(OD) modes has shown that not the isotope isolation but the dynamic disorder of the crystal is the major contributor to the spectral bandwidths.

The application of low temperature infra-red spectroscopy to studies of iron substitution in tricalcium aluminate (C 3A)

Low temperature IR spectroscopy has been used to study the extent of solid solution of Fe in C 3A. The intensity of the bands in the IR spectra obtained in sufficient to permit peak ratios to be used (for the first time) as an aid to determining the extent and nature of the solid solution.

IR investigation of homo- and copolymers of oxides of ethylene and propylene

The materials investigated by IR spectroscopy homo- and copolymers of oxides of ethylene and propylene, differing as to composition and MW, and as to the distribution of monomer units. The analysis covered the range 700–4000 cm −1, the temperature range extending from −90 to 20°, it was found that the method of low temperature IR spectroscopy mya be used to measure the length distribution of hydroxynthylene sequences.

Polymerization of Isobutyi Vinyl Ether by Diethylaluminum Chloride. Requirement of Cocatalyst

In the polymerization of isobutyi vinyl ether, Et2AlCl was inactive by itself and highly activated by oxygen. A limited amount of oxygen contacted with Et2AlCl at −78°C gave a stereoregular polymer in a good yield. The catalytically active species was stable only at low temperatures. Iodometrical titration and low temperature IR spectroscopy indicated that the concentration of the active species was proportional to that of the peroxide, e.g., EtAl(OOEt)Cl, a thermally unstable intermediate formed in the course of oxidation of Et2AlCl by oxygen. EtAl(OOCMe2Ph)Cl catalyses the process in a similar fashion to that of the “low temperature Et2AlCl–O2catalyst system.” The oxidation of Et2AlCl and the catalytic activity of the products are studied. The effects of carbon dioxide are reasonably interpreted in terms of the competitive coordination between oxygen and carbon dioxide toward organo-aluminums.

Infrared Spectroscopy at Subambient Temperatures

Abstract The development of low-temperature IR spectroscopy has been rather sporadic. The first published investigations appear to be those of Hettner [1] in 1932. Little further effort was devoted to the area until the 1940s when several investigators became interested in the various spectral effects which took place with both simple and complex molecules on lowering the temperature. This work in the 1940s and early 1950s has been reviewed by Sheppard [2] and by Hornig [3]. Most of the theoretical principles involved were elucidated in this period and a good deal of the potential of the technique was envisioned. Nevertheless, low-temperature IR spectroscopic investigations during the next 10 to 15 years were limited primarily to applications in the area of conformational isomerism. Workers in this area normally are interested only in gross spectral changes occurring during liquid-solid phase changes. In the late 1960s there occurred a general revival of interest in low-temperature IR spectroscopy in anot...