Apparatus for fast time-resolved infrared dectection of reaction intermediates in the solution photochemistry of transition-metal carbonyls

Abstract

An apparatus is described for time-resolved i.r. spectroscopy of metal carbonyls in solution, based on a c.w. CO laser for i.r. spectroscopy and either a u.v. excimer laser or an Xe flash lamp for photolysis. Typical performance data are: tuning range, 2020–1700 m^–1(tunable in steps of 4 cm^–1); i.r. detection risetime, 700 ns; sensitivity, an absorbance change of 10^–3 can be detected with an S/N ratio of 5 on single shot. These specifications are supported by results from the photochemistry of [(C₅H₅)Fe(CO)₂]₂ in cyclohexane solution, including high-pressure experiments and dual-wavelength photolysis.