Construction Of An Instrument For Doing Fast Time-Resolved Infrared Spectroscopy

We have designed and assembled a system for doing flash photochemical studies of organotransition metal carbonyl complexes with fast time-resolved infrared detection. Photolysis is with conventional xenon flashlamps (400J/flash) and time resolved infrared absorption spectra are measured with a diode laser (Laser Photonics, Inc.) and indium antimonide detector operating in the range 1700 - 2100 cm -1. Signals are collected and averaged on a digital oscilloscope (LeCroy 9410) for subsequent computer storage and analysis. The waveform is downloaded to the computer where calculations of percent transmittance and absorbance vs time are calculated. The information is then transferred to a spreadsheet where further calculations can be done and the information can be plotted. The spectral range of the probe laser corresponds to the CO stretching region in transition metal carbonyl complexes thus making it suitable for detailed time resolved studies of the kinetics and mechanisms of these species