Time-resolved resonance Raman apparatus

Fig. 1 shows a schematic of the time resolved resonance Raman apparatus for radiation chemical studies. The essential components of the experimental set up are (a) a pulsed electron radiation source for inducing the reactions, (b) a tunable pulsed laser to probe the Raman scattering, (c) a Spex double monochromator for analyzing the scattered light, and (d) a gated detector for recording the spectra. 

Figure 1. Schematic of the time-resolved resonance Raman apparatus for radiation-chemical studies.

Figure C3.1.11. Apparatus for pump-probe time-resolved resonance Raman spectroscopy. (From Varotsis C and Babcock G T 1993 K4ethods Enzymol. 226 409-31.)...

Towrie, M., Grills, D.C., Dyer, L., Weinstein, J.A., Matousek, R, Barton, R., Bailey, R.D., Subramaniam, N., Kwok, W.M., Ma, C., Phillips, D., Parker, A.W. and George, M.W. (2003) Development of a broadband picosecond infrared spectrometer and its incorporation into an existing ultrafast time-resolved resonance Raman, UV/visible, and fluorescence spectroscopic apparatus. Appl. Spectrosc., 57, 367-380. 

A tunable pulsed laser Raman spectrometer for time resolved Raman studies of radiation-chemical processes is described. This apparatus utilizes the state of art optical multichannel detection and a-nalysis techniques for data acquisition and electron pulse radiolysis for initiating the reactions. By using this technique the resonance Raman spectra of intermediates with absorption spectra in the 248-900 nm region, and mean lifetimes > 30 ns can be examined. This apparatus can be used to time resolve the vibrational spectral o-verlap between transients absorbing in the same region, and to follow their decay kinetics by monitoring the well resolved Raman peaks. For kinetic measurements at millisecond time scale, the Raman technique is preferable over optical absorption method where low frequency noise is quite bothersome. A time resolved Raman study of the pulse radiolytic oxidation of aqueous tetrafluoro-hydroquinone and p-methoxyphenol is briefly discussed. 

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