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A Variable Temperature Cell for the Measurement of Infrared Spectra

Volume 28, Number 5 (Oct. 1974) Page 479-481

Štokr, J.; Růžička, Z.; Ekwal, S.R.


Temperature and time changes of infrared spectra may be used for studies of kinetic processes. Since the measurements often require low temperatures within a wide temperature interval and the compounds used are subjected to rapid cooling, special infrared cells must be used in these cases. The requirements for such cells are to a certain extent satisfied by an infrared cell which may be used without entrance and exit optical windows and where a stream of cooling nitrogen vapor prevents atmospheric water vapor from condensing on the cooled cell. The simple design of this cell makes possible a rapid cooling of the sample either by immersing it into liquid nitrogen or by spraying the sample on a precooled disc. Such a cell was used for the measurement of the activation energy of the conformational transition in chlorocyclohexane. However, the cell cannot be used below — 150°C because below this temperature condensation of carbon dioxide on the sample pellets of the cell takes place.