Photochemical quantum yields depend on photon flux, molar absorptivity, and rate constants. Actinometers are compounds with well-defined quantum yields and other photochemical properties that are used to derive the flux of light sources and convert photochemical rate constants into quantum yields for unknown reactions. O-nitrobenzaldehyde (NB) is a robust actinometer with a wavelength independent quantum yield 280-400 nm in both solids and liquids. However, the quantum yield of NB ranges from 0.4-0.5, creating an 18% uncertainty in fluxes and quantum yields derived using o-nitrobenzaldehyde. This study aims to derive the quantum yield of NB and verify the quantum yield using potassium ferrioxalate. To derive the quantum yield, the rate of NB reaction, the molar absorptivity, and photon flux were 0.0266 s-1, 4.005�103 M-1, and 7.06�10-6 mol photons s-1L-1, respectively. The measured quantum yield, 0.041, will be used to derive photon flux and quantum yield values for unknown photochemical reactions.

Determination and verification of the o-nitrobenzaldehyde quantum yield

243rd National Meeting (2012)

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