THE USE OF DIFFUSE-REFLECTANCE INFRARED FOURIER-TRANSFORM SPECTROSCOPY TO MONITOR REACTIONS IN LOW-TEMPERATURE FILMS AND MATRICES

A reactor has been designed which should enable organic photochemistry to be carried out on a preparative scale at very low temperatures (ca. 10-40 K), in either thin films or in inert matrices (e.g. Ar or N-2). The intention is to monitor the progress of these reactions using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Accordingly a Bomem MB-100 FTIR spectrometer has been modified to allow DRIFTS measurements to be made on cooled surfaces enclosed within a vacuum chamber. The early studies have shown that satisfactory DRIFT spectra may be easily obtained for a fairly dilute (1:500) matrix of acetone in N-2, and that photochemical decompositions of a diazo compound and benzoyl azide can be followed with ease.