Photodetachment-modulated electron

We have recently described another spectroscopic rnethod for observing IM reactions at atmospheric pressure that utilizes the photodetachment-modulated electron capture detector (PDM-ECD) as a means of monitoring the negative ions either consumed or produced in an IM reaction. The reaction of interest is made to occiu in a steady-state flow-through reactor in which ionization of the buffer gas is continuously caused by a Ni-on-Pt foil beta emitter. A chopped light beam of... 

Figure 4, Structure of a series of alkyl bromides and the rate constants (1 O " cm s ) for the IM reaction of each compound with the chloride ion, determined by the photodetachment-modulated electron capture detector (PDM-ECD) in 10% argon-inmethane buffer gas at atmospheric pressure and 125 °C. ...

Figure 5. The photodetachment spectra of Az measured by the photodetachment-modulated electron capture detector (PDM-ECD) in 10% argon-in-methane buffer gas at three different temperatures.

Finally, electrons have been generated with nanosecond pulses from the KrF exciplex laser at 248 nm via photodetachment of OH and Cl in aqueous and methanol solutions, and could be via one-photon photoionization in liquids with the ArF laser at 193 nm, and via one and two-photon processes in aqueous naphthol and naphtholate with nanosecond pulsed nitrogen lasers at 337 nm. With the improved fluxes and short pulses now available from gain modulation techniques applied to the TEA exciplex lasers, semiconductor lasers and F-center lasers, they may prove to be convenient sources for future studies of electron relaxation and transfer processes from the ultraviolet to infrared region. 

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