The influence of solute absorbance in laser flash photolysis - actinometry in experiment and theory at non-vanishing absorbance

摘要

Laser flash photolysis set-ups are commonly operated with non-vanishing absorbance in order to obtain a maximum signal-to-noise ratio. The exponential law of light absorption leads to non-linear equations. An example of their mathematical treatment is given and compared with experiments using the benzophenone-4-carboxylic acid actinometer (excitation wavelength: 308 nm) up to a solute absorbance of 6. The influence of geometry in concert with solute absorbance on the signal reading is modelled. Two approximated mathematical solutions of the ensuing non-linear equations are presented together with their application for an optimisation of laser flash photolysis experiments.