Accession Number:
AD0739141
Title:
Photoexcitation of Hydrated Electrons Using a Q-Switched Ruby Laser,
Descriptive Note:
Corporate Author:
BRITISH COLUMBIA UNIV VANCOUVER DEPT OF CHEMISTRY
Personal Author(s):
Report Date:
1971-02-15
Pagination or Media Count:
5.0
Abstract:
The lifetime of the photoexcited state of the hydrated electron in liquid water at room temperature is shown to be less than 6 x 10 to the -12 sec following photoexcitation at 694 nm, a wavelength very close to lambdamax. This has implications concerning the nature of the optical transition involved and may suggest that the absorption band is a photoionisation efficiency profile rather than an electronic transition to a bound excited state. The absorbance of hydrated electrons produced by uv flash photolysis was measured at very high light fluxes using a Q-switched ruby laser under conditions where cryptocyanine and methylene blue solutions showed marked nonlinear absorption due to saturation of optical transitions. Whereas the dye solutions showed diminished absorbance and a shortening of the laser pulse at high light intensities, hydrated electrons gave identical absorbance at all intensities, varied over 7 orders of magnitude, up to 200 photons per hydrated electron per sq cm of the light beam. Author
Descriptors:
Subject Categories:
- Physical Chemistry