Organometallic Photochemistry at the Solid/Gas Interface. Photochemistry of Surface-Confined Cobalt Tetracarbonyl Monitored by Fourier Transform Infrared Photoacoustic Spectroscopy

摘要

We wish to report the photochemistry of surface-confined -Co(CO)4 fragments exposed to reactive gases. Such photochemistry is of importance in establishing primary events following excitation of the molecular entity attached to the surface and is of relevance to the photoactivation of surface-confined catalysts. We apply, for the first time, the technique of Fourier transform infrared photoacoustic spectroscopy (FTIR/PAS) to monitor the photoreactions of a species on the surface including in situ monitoring of reactions involving a gas phase species. Without any sample manipulation or preparation, this technique has allowed characterization of the photochemistry of surface species with the molecular level specificity generally possible when infrared absorption spectroscopy is used to monitor reactions of metal carbonyls in homogeneous solution. The results herein establish FTIR/PAS as a technique of unequalled capability in monitoring such surface chemistry.